Frederick County, MD: risk-assessment baseline packet, release 2026-10

Summary

Plan status as of 2026-09-30: Approved, expires 2027-05-18. Plan: Frederick County Hazard Mitigation Plan (FEMA plan 108151), approved 2022-05-19.

Update: FEMA tracker shows a plan in progress.

Since the plan was approved on 2022-05-19: 1 new hazard declaration (1 incident) and 169 NOAA Storm Events records; details under "What changed since your last plan".

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Inland Flooding ($32,236,722 a year), Tornado ($3,496,516) and Heat Wave ($3,099,251).

The tables that follow are organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B (B1-a to B2-c); each heading says which item its tables support.

Terms used

EAL:: expected annual loss: FEMA's modeled average yearly loss from a hazard.
NRI:: FEMA's National Risk Index (version 1.20, December 2025).
NFIP:: National Flood Insurance Program.
RL, SRL:: repetitive loss and severe repetitive loss: flood-insured properties with repeated claims (definitions in B2-c).
FMA, HMGP:: Flood Mitigation Assistance and Hazard Mitigation Grant Program, FEMA mitigation grants.
PA:: FEMA Public Assistance: disaster aid to governments and some nonprofits.
Zone-level:: NOAA logged the event for a National Weather Service forecast zone, which may include parts of neighboring counties.
County-coded:: NOAA logged the event to this county.
FIPS:: the federal code for a place; 24021 is this area.
D0 to D4:: U.S. Drought Monitor categories, from abnormally dry (D0) to exceptional drought (D4).
F/EF, EFU:: Fujita and Enhanced Fujita tornado ratings; EFU is an unrated tornado.
kt, CONUS:: knots (1 kt is about 1.15 mph); the contiguous United States.
CFR:: Code of Federal Regulations.
A4-a, E1-a:: other items of FEMA's Local Mitigation Plan Review Tool (sources, and changes since the last plan).
Dollars:: nominal (as reported, labeled with the year), not adjusted for inflation.

Plan clock

Status:: Approved, expires 2027-05-18
Plan:: Frederick County Hazard Mitigation Plan (FEMA plan 108151)
Approved:: 2022-05-19
Days to expiry:: 230
Update underway:: FEMA tracker shows a plan in progress

What changed since your last plan (approved 2022-05-19)

New federal declarations:: 1 new hazard declaration (1 incident): EM-3634-MD (Severe Winter Storm)
Storm Events records since approval:: 169 records (data through 2026-06-30)
Repetitive loss now:: FMA RL 0, SRL 6 (44 CFR 77.2); any definition: 25
Repeat-flood change:: this release sets the baseline count.

Sources: 1, 2, 4, 6 (numbered list at the end)

Plan status for every jurisdiction listed in this county: 13 rows, in the section "Plan clock: Plan status for every jurisdiction listed in this county" on the following pages.

State plan status and tribal plans in this state: see the state page.

Plan clock

Plan status for every jurisdiction listed in this county

Source: 1

Jurisdiction	Type	Status	Plan	Approved	Expires	Days to expirynegative = days since expiry	Update underway	Notes
Frederick County	County	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress
Brunswick city	City	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-05-31
Burkittsville town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-27
Emmitsburg town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-11-07
Frederick city	City	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-06-08
Middletown town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-10-10
Mount Airy town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan approvable pending adoption	Not yet eligible: adopt the approved plan. this jurisdiction approved 2022-11-07
Myersville town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-07-12
New Market town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-08-11
Rosemont village	Village	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-03-27
Thurmont town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-05-24
Walkersville town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2022-12-14
Woodsboro town	Town	Approved, expires 2027-05-18	Frederick County Hazard Mitigation Plan (FEMA plan 108151)	2022-05-19	2027-05-18	230	FEMA tracker shows a plan in progress	this jurisdiction approved 2023-05-09

Supports FEMA checklist item B1-a: hazard identification

Hazards NRI does not cover (local data needed)

dam failure (incl. upstream dams)
levee failure
flash flood as its own subtype
ice jams
debris flows
erosion (riverine and coastal)
land subsidence and sinkholes
expansive soils

The 18 National Risk Index hazards, ranked by expected annual loss (EAL)

Sources: 5, 6

Rank by EAL	Hazard	NRI risk rating	EAL rating	EAL buildingsmodeled dollars per year	EAL agriculturemodeled dollars per year	Cost of expected deaths and injuriesFEMA's dollar value per year, not property damage	EAL total (see note)modeled dollars per year	Storm Events records, 1996 to 2026-06-30count	Storm Events coverage note
1	Inland Flooding	Relatively Moderate	Relatively Moderate	$26,535,414	$23,421	$5,677,887	$32,236,722	310
2	Tornado	Relatively Moderate	Relatively Moderate	$1,735,406	$3,981	$1,757,129	$3,496,516	22
3	Heat Wave	Relatively Moderate	Relatively Moderate	under $1	$1,812	$3,097,438	$3,099,251	45
4	Hurricane	Relatively Low	Relatively Moderate	$1,969,427	$553,749	$80,975	$2,604,152	2
5	Strong Wind	Relatively Moderate	Relatively High	$369,244	$61,612	$1,589,970	$2,020,825	616	Includes 34 High Wind and 28 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
6	Earthquake	Relatively Low	Relatively Low	$1,323,934	n/a	$367,496	$1,691,430		Storm Events does not record earthquakes.
7	Lightning	Relatively High	Relatively High	$93,342	n/a	$1,135,047	$1,228,389	23
8	Hail	Relatively Moderate	Relatively Moderate	$1,019,637	$36,466	$1,503	$1,057,605	70
9	Drought	Relatively Moderate	Relatively Moderate	n/a	$898,243	n/a	$898,243	12
10	Cold Wave	Relatively Low	Relatively Low	$73,775	$215,434	$421,186	$710,396	64	Includes 45 Frost/Freeze records (outside NRI's Cold Wave definition; counted in this table and in B1-d, not in the B1-e descriptor).
11	Winter Weather	Relatively High	Relatively High	$48,799	$61	$596,027	$644,887	226
12	Ice Storm	Relatively Low	Relatively Moderate	$39,977	n/a	$111,215	$151,192	8
13	Wildfire	Very Low	Very Low	$15,469	$10	$3,286	$18,765	0	No recorded events in Storm Events since 1996 (data through 2026-06-30).
14	Landslide	Relatively Low	Very Low	$6,053	n/a	$591	$6,643	0	No recorded events in Storm Events since 1996 (data through 2026-06-30).
15	Avalanche	Very Low	Very Low	$0	n/a	$66	$66	0	No recorded events in Storm Events since 1996 (data through 2026-06-30).

Total = buildings + agriculture + population equivalence; FEMA values each expected death (or 10 injuries) at $13.7 million (2024 dollars).

NRI risk rating combines expected annual loss with social vulnerability and community resilience; EAL rating rates expected annual loss alone. Both compare this county with all U.S. counties.

Local data needed: state and local wildfire and landslide records (Storm Events records these hazards only in part).

Not applicable to this county per NRI, with no federal declaration and no Storm Events record since 1996: coastal flooding, tsunami and volcanic activity. That is the evidence for leaving them out of the plan.

The state hazard mitigation plan also lists hazards for this county; FEMA asks the plan to explain any hazard it leaves out.

Supports FEMA checklist item B1-b: hazard location

Affects the whole county (national data give no location within it): Cold Wave, Drought, Hail, Heat Wave, Ice Storm, Lightning, Strong Wind and Winter Weather.

Inland Flooding: The FEMA Flood Insurance Rate Map (FIRM) is the required location source for flooding. See the FEMA Flood Map Service Center (https://msc.fema.gov) for this county.

Hazards that vary within the county: highest-rated census tracts

Source: 5

Hazard	Highest-rated census tractsNRI risk rating, score 0 to 100
Avalanche	tract 7529 (Very Low, 12.1); tract 7516 (Very Low, 11.8); tract 7525.02 (Very Low, 11.3)
Earthquake	tract 7510.03 (Relatively Low, 70.6); tract 7506 (Relatively Low, 68.4); tract 7722 (Relatively Low, 68.0)
Hurricane	tract 7523.02 (Relatively Low, 77.6); tract 7675 (Relatively Low, 76.5); tract 7510.03 (Relatively Low, 76.4)
Landslide	tract 7529 (Relatively Low, 92.5); tract 7522.01 (Relatively Low, 90.4); tract 7528.02 (Relatively Low, 88.2)
Tornado	tract 7510.03 (Relatively Moderate, 60.7); tract 7505.05 (Relatively Moderate, 57.0); tract 7523.02 (Relatively Moderate, 55.5)
Wildfire	tract 7529 (Relatively Low, 77.3); tract 7528.02 (Relatively Low, 77.0); tract 7528.01 (Very Low, 66.4)

Up to 3 census tracts per hazard, highest National Risk Index rating first, then highest score; a tract number is the Census tract number (for example 7529 is Census Tract 7529). FEMA's Resilience Analysis and Planning Tool maps the National Risk Index for every tract: https://www.fema.gov/emergency-managers/practitioners/resilience-analysis-and-planning-tool

Supports FEMA checklist item B1-c: hazard extent

Extent: scale, observed range and worst recorded event per hazard

Sources: 6, 7

Hazard	Scale	Recordscount and years	Observed range	Worst recorded event	Most damaging (when different)	How it applies to jurisdictions	Note
Avalanche	none (count and damage only)	0
Cold/Wind Chill, Extreme Cold/Wind Chill	wind chill	19 records, 1998 to 2026 (19 zone-level)	1 day to 11 days (median 2 days); 17 with a recorded value	11 consecutive days, 2026-01-23 to 2026-02-02, zone-level		Countywide (zone-level records).
Frost/Freeze (outside NRI's Cold Wave definition)	crop damage	45 records, 1997 to 2020 (45 zone-level)		Frost/Freeze, 1997-04-10, $112,000 crop damage (1997 dollars); NWS zone MDZ004		Countywide (zone-level records).
Drought	U.S. Drought Monitor scale (D0 to D4)	12 records, 1997 to 2007 (12 zone-level)	22 days to 140 days (median 31 days); 5 with a recorded value	140 days (about 4.6 months), 1999-05-01 to 1999-09-17, a run of 5 consecutive Storm Events drought records, zone-level	Drought, 1997-07-01, property not reported; $14,200,000 crops (zone total, 1997 dollars)	Countywide (zone-level records).	Storm Events enters a drought at D2 or worse east of the Rockies and D3 or worse from the Rockies west (NWS Instruction 10-1605); NRI drought counts D3 and D4 only.
Earthquake	Modified Mercalli (local data)	0					Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail	hail size (inches)	86 records, 1957 to 2025	0.75 in to 2.5 in (median 1 in); 85 with a recorded value	2.5 in hail, 2018-05-15; same size also recorded on 2000-05-10	Hail, 2008-07-26, $5,000 property; $5,000 crops (2008 dollars)	Event records naming jurisdictions in the plan: Frederick city (18 records), Myersville town (5 records), Brunswick city (4 records), Burkittsville town (3 records), Walkersville town (3 records), Thurmont town (2 records), Middletown town (1 record), New Market town (1 record), Woodsboro town (1 record).
Excessive Heat, Heat	heat index (in event narratives)	45 records, 1996 to 2025 (45 zone-level)	1 day to 8 days (median 2 days); 34 with a recorded value	8 consecutive days, 2002-08-12 to 2002-08-19, zone-level		Countywide (zone-level records).	Heat records from November to March (unseasonable warmth, not a heat wave) are counted but not used for the longest run.
Hurricane, Tropical Storm, Tropical Depression	Saffir-Simpson	2 records, 2008 to 2011 (2 zone-level)		Strongest recorded: Tropical Storm record, 2011-08-27 to 2011-08-28, $5,000 property; crops not reported (2011 dollars); NWS zone MDZ004		Countywide (zone-level records).	Storm Events files every zone of a storm's episode under the storm's type; flooding from the storm is filed as Flood or Flash Flood records.
Ice Storm	Sperry-Piltz ice scale (local data)	8 records, 1996 to 2022 (8 zone-level)		Ice Storm, 1998-01-15, $10,000 property; $15,000 crops (1998 dollars); NWS zone MDZ004		Countywide (zone-level records).
Flash Flood, Flood, Lakeshore Flood	damage and flood days (flood depth: FIRM)	310 records, 1996 to 2025 (23 zone-level)		Flash Flood, 2018-05-15, $43,200,000 property; $0 crops (2018 dollars)		Event records naming jurisdictions in the plan: Emmitsburg town (31 records), Frederick city (19 records), Walkersville town (12 records), Thurmont town (11 records), Brunswick city (8 records), Woodsboro town (4 records), Middletown town (3 records), Myersville town (2 records), New Market town (2 records), Rosemont village (1 record). Zone-level records (23) apply countywide.	Flood depth: see the FEMA Flood Insurance Rate Map. Storm Events damage is often $0 or blank for floods, major ones included; FEMA Public Assistance by declaration (B1-d) shows which floods cost the most.
Debris Flow	none (count and damage only)	0
Lightning	annualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)	23 records, 1996 to 2021		Lightning, 2002-08-03, damage not reported, 1 direct death	Lightning, 2000-08-07, $750,000 property; crops not reported (2000 dollars)	Event records naming jurisdictions in the plan: Frederick city (6 records), Brunswick city (1 record), Middletown town (1 record), New Market town (1 record), Thurmont town (1 record), Walkersville town (1 record), Woodsboro town (1 record).	Storm Events lists lightning with damage or casualties.
High Wind and Strong Wind (outside NRI's Strong Wind definition)	wind speed (kt and mph)	62 records, 1996 to 2026 (60 zone-level)	30 kt (35 mph) to 66 kt (76 mph) (median 50 kt (58 mph)); 43 with a recorded value	66 kt (76 mph) measured gust, High Wind, 2025-02-16; NWS zone MDZ004	High Wind, 2012-10-29, $1,210,000 property; $0 crops (zone total, 2012 dollars)	Event records naming jurisdictions in the plan: Thurmont town (1 record), Walkersville town (1 record). Zone-level records (60) apply countywide.
Thunderstorm Wind	wind speed (kt and mph)	629 records, 1958 to 2026	39 kt (45 mph) to 76 kt (87 mph) (median 52 kt (60 mph)); 517 with a recorded value	76 kt (87 mph), measurement type not recorded, Thunderstorm Wind, 1992-01-14	Thunderstorm Wind, 2026-06-14, $1,000,000 property; crops not reported (2026 dollars)	Event records naming jurisdictions in the plan: Frederick city (46 records), Brunswick city (21 records), Middletown town (20 records), Myersville town (17 records), New Market town (17 records), Thurmont town (17 records), Emmitsburg town (16 records), Walkersville town (11 records), Woodsboro town (10 records), Rosemont village (8 records); and 2 more jurisdictions (see the Excel file).
Tornado	Enhanced Fujita (Fujita before Feb 2007)	38 records, 1952 to 2021	F/EF0 to F/EF3 (median F/EF1); 38 with a recorded value	F3 tornado, 1983-05-22, 1 mi path length (whole path, pre-1996), 37 yd wide, $25,000 property; crops not recorded (1983 dollars)	Tornado, 1999-08-14, $800,000 property; crops not reported (1999 dollars)	Event records naming jurisdictions in the plan: Frederick city (3 records), Brunswick city (2 records), Mount Airy town (1 record), Rosemont village (1 record), Thurmont town (1 record), Woodsboro town (1 record).	Before 1996 a tornado is listed once, under the county where it began, with its whole path's rating and length; from 1996 on, each county lists its own segment. Length is not used to rank tornadoes (see Methods).
Wildfire	acres burned (local data)	0
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleet	none in data (snowfall: local data)	226 records, 1996 to 2026 (225 zone-level)		Winter Storm, 2003-02-14, $200,000 property; crops not reported (2003 dollars); NWS zone MDZ004		No event record names a jurisdiction in the plan. Zone-level records (225) apply countywide.

Where a hazard names more than 10 jurisdictions, the table lists the 10 with the most records; every one is in the Excel file, sheet "B1-c Extent".

In event narratives only (local data needed): wind chill, temperature, heat index, ice thickness, acres burned and snow depth; any physical measure of avalanche, debris flow and lightning.

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records from zones that no NWS zone-county file places in this county (mostly before 2020) are not counted here (the Methods page explains the zone matching).

Dollars are nominal (as reported), labeled with the year; not adjusted for inflation.

Supports FEMA checklist item B1-d: previous occurrences

Federal declarations for this county: 23 declarations covering 19 separate hazard incidents counted in this packet (declarations for the same incident count once; non-natural and evacuation-only declarations are not counted).

Federal disaster declarations for this county

Sources: 1, 2, 3

Declared	Incident began	FEMA number	Type	Title	Mapped hazard	County Public Assistancefederal share obligated, nominal dollars	Flags	Notes
2026-01-24	2026-01-23	EM-3634-MD	Emergency	Severe Winter Storm	Winter Weather	no Public Assistance recorded	new since last plan; within last 5 years
2020-03-26	2020-01-20	DR-4491-MD	Major disaster	COVID-19 Pandemic	Non-natural, not counted	$17,872,911.05
2020-03-13	2020-01-20	EM-3430-MD	Emergency	COVID-19	Non-natural, not counted	no Public Assistance recorded		same incident as DR-4491
2018-06-25	2018-05-15	DR-4374-MD	Major disaster	Severe Storms and Flooding	Inland Flooding	$4,623,608.13
2016-03-04	2016-01-22	DR-4261-MD	Major disaster	Severe Winter Storm and Snowstorm	Winter Weather	$1,711,274.58
2012-11-20	2012-10-26	DR-4091-MD	Major disaster	Hurricane Sandy	Hurricane	$964,316.19
2012-10-28	2012-10-26	EM-3349-MD	Emergency	Hurricane Sandy	Hurricane	no Public Assistance recorded		same incident as DR-4091
2011-08-27	2011-08-26	EM-3335-MD	Emergency	Hurricane Irene	Hurricane	$25,929.70
2010-05-06	2010-02-05	DR-1910-MD	Major disaster	Severe Winter Storms and Snowstorms	Winter Weather	$1,060,682.63
2005-09-13	2005-08-29	EM-3251-MD	Emergency	Hurricane Katrina Evacuation	Hurricane: evacuation support, not a local hazard event; not counted	no Public Assistance recorded
2003-09-19	2003-09-18	DR-1492-MD	Major disaster	Hurricane Isabel	Hurricane	$573,511.43
2003-03-14	2003-02-14	EM-3179-MD	Emergency	Snow	Winter Weather	$400,921.30
2000-04-10	2000-01-25	DR-1324-MD	Major disaster	Severe Winter Storm	Winter Weather	$337,334.07
1996-09-17	1996-09-06	DR-1139-MD	Major disaster	Severe Storms and Flooding Assoc with Tropical Storm Fran	Hurricane (primary); also designated: Inland Flooding	PA not declared for this county
1996-01-23	1996-01-19	DR-1094-MD	Major disaster	Severe Storms and Flooding	Inland Flooding	no Public Assistance recorded
1996-01-11	1996-01-06	DR-1081-MD	Major disaster	Blizzard of 96 (Severe Snow Storm)	Winter Weather	no Public Assistance recorded
1994-03-16	1994-02-08	DR-1016-MD	Major disaster	Severe Winter Weather and Ice Storms	Winter Weather (primary); also designated: Ice Storm	no Public Assistance recorded
1993-03-16	1993-03-13	EM-3100-MD	Emergency	Severe Snowfall & Winter Storm	Winter Weather	no Public Assistance recorded
1979-09-14	1979-09-14	DR-601-MD	Major disaster	Severe Storms, Tornadoes & Flooding	Inland Flooding; Tornado	no Public Assistance recorded
1976-10-14	1976-10-14	DR-522-MD	Major disaster	Severe Storms & Flooding	Inland Flooding	no Public Assistance recorded
1975-10-04	1975-10-04	DR-489-MD	Major disaster	Heavy Rains & Flooding	Inland Flooding	no Public Assistance recorded
1972-06-23	1972-06-23	DR-341-MD	Major disaster	Tropical Storm Agnes	Inland Flooding (primary); also designated: Hurricane	no Public Assistance recorded
1971-08-17	1971-08-17	DR-309-MD	Major disaster	Severe Storms & Flooding	Inland Flooding	no Public Assistance recorded

County Public Assistance: applicants the FEMA record places in this county, including any state agencies FEMA files there; statewide rows are listed on the state page; federal share obligated, nominal dollars.

Statewide declarations

Source: 2

Declared	Incident began	FEMA number	Type	Title	Mapped hazard
1962-03-09	1962-03-09	DR-127-MD	Major disaster	Severe Storms, High Tides & Flooding	Inland Flooding (primary); also designated: Coastal Flooding

FEMA recorded these with designated area Statewide and no county, so they are listed on every county page in the state and not counted with county rows. Local data needed: whether each one affected this county.

Public Assistance filed under this county for declarations that do not list it: 1 row, $18,663.97

Sources: 2, 3

FEMA number	Declared	Title	Applicant	PA obligatedfederal share obligated, nominal dollars
DR-4170-MD	2014-04-10	Snowstorm	Mount Airy	$18,663.97

FEMA's Public Assistance summaries file these applicants under this county, but FEMA's declaration rows for these disasters do not designate it (an electric cooperative or district serving several counties, for example). Not in any declaration row above and not counted.

Public Assistance not placed in any Maryland county: 1 row, $112,415.86; listed on the Maryland state page.

Source: 3

Previous occurrences by hazard, with explicit no-event rows

Sources: 2, 6, 7

Hazard	Storm Events records, all years on file(years in the Period column)	Since plan approvalrecords	In the 12 months before plan approvalrecords	Last 5 yearsrecords	Declared incidents, all yearsseparate disasters	Declared since approvalseparate disasters	Period	Statement
Avalanche	0	0	0	0	0	0	1996 to 2026-06-30	No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Cold Wave	64	4	0	4	0	0	1996 to 2026-06-30	Includes 45 Frost/Freeze records.
Drought	12	0	0	0	0	0	1996 to 2026-06-30
Earthquake	0	0	0	0	0	0		Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail	86	7	0	7	0	0	1955 to 2026-06-30
Heat Wave	45	1	1	1	0	0	1996 to 2026-06-30
Hurricane	2	0	0	0	5	0	1996 to 2026-06-30
Ice Storm	8	1	0	1	1	0	1996 to 2026-06-30
Inland Flooding	310	6	68	19	8	0	1996 to 2026-06-30
Landslide	0	0	0	0	0	0	1996 to 2026-06-30	No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Lightning	23	0	1	0	0	0	1996 to 2026-06-30
Strong Wind	691	126	32	131	0	0	1955 to 2026-06-30	Includes 34 High Wind and 28 Strong Wind records.
Tornado	38	0	0	0	1	0	1950 to 2026-06-30
Wildfire	0	0	0	0	0	0	1996 to 2026-06-30	No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Winter Weather	226	24	7	31	8	1	1996 to 2026-06-30

Notable Storm Events records

Sources: 1, 6, 7

Date	Event type	Magnitude or extent	Damagenominal dollars	Deaths, injuriesdirect only	Location	Flags	Why listed
2025-02-16	High Wind	66 kt (76 mph) measured gust	$0 property; $0 crops (zone total, 2025 dollars)	0, 0	NWS zone MDZ004 (FREDERICK), zone-level	new since last plan; within last 5 years	B1-c worst recorded: High Wind and Strong Wind
2022-12-23	High Wind	50 kt (58 mph) measured gust	$0 property; $0 crops (zone total, 2022 dollars)	1, 0	NWS zone MDZ004 (FREDERICK), zone-level	new since last plan; within last 5 years	deaths or injuries recorded
2019-07-21	Excessive Heat		damage not reported	1, 0	NWS zone MDZ004 (FREDERICK), zone-level		deaths or injuries recorded
2018-05-15	Flash Flood		$43,200,000 property; $0 crops (2018 dollars)	0, 0	FT DETRICK to GROVE		B1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
2018-05-15	Hail	2.5 in	damage not reported	0, 0	FREDERICK		B1-c worst recorded: Hail
2011-08-27	Tropical Storm		$5,000 property; crops not reported (zone total, 2011 dollars)	0, 0	NWS zone MDZ004 (FREDERICK), zone-level		B1-c worst recorded: Hurricane, Tropical Storm, Tropical Depression
2006-06-27	Flash Flood		$500,000 property; crops not reported (2006 dollars)	5, 1	COUNTYWIDE		deaths or injuries recorded
2002-08-12	Heat		damage not reported	0, 0	NWS zone MDZ004 (FREDERICK), zone-level		B1-c worst recorded: Excessive Heat, Heat
2002-08-03	Lightning		damage not reported	1, 0	FREDERICK		B1-c worst recorded: Lightning
1999-05-01	Drought		damage not reported	0, 0	NWS zone MDZ004 (FREDERICK), zone-level		B1-c worst recorded: Drought
1992-01-14	Thunderstorm Wind	76 kt (87 mph), measurement type not recorded	damage not recorded (pre-1996 record)	0, 0	location not recorded		B1-c worst recorded: Thunderstorm Wind
1983-05-22	Tornado	F3, 1 mi path length (whole path, pre-1996), 37 yd wide	$25,000 property; crops not recorded (1983 dollars)	0, 0	location not recorded		B1-c worst recorded: Tornado

The full list is in the Excel file, sheet "B1-d Storm Events history" (1,505 rows).

Location is the place NOAA recorded, as written in its data; it need not be a jurisdiction in this plan.

Local data needed: state-declared emergencies, from your state emergency management agency (federal data do not include them).

FEMA's declaration data list no tribal or special-area declarations for this state.

Supports FEMA checklist item B1-e: probability of future events

Probability: FEMA annualized frequency and descriptor per hazard

Sources: 5, 6

Hazard	FEMA annualized frequency (modeled)unit per row	Unit	In plain terms	Descriptor	Descriptor basis	NRI events or days in its record period (hail, wind and tornado are area-weighted, so can be fractional)	NRI period	Location	Note
Avalanche	0.01	events per year	about 1 in 100 years	Possible	FEMA annualized frequency (modeled)	0	1994 to 2023 (30 years)	see B1-f	0.01 is NRI's minimum avalanche frequency for a county in an avalanche susceptibility zone; NRI records no avalanche here, so the descriptor reflects the floor, not local events.
Cold Wave	1.79	event-days per year	about 1.79 days per year	Likely	Storm Events event-days in 10 of 30 years, 1996 to 2025 (33.3%)	34	2005-11-12 to 2024-11-12 (19 years)	countywide
Drought	3.97	event-days per year	about 3.97 days per year	Likely	Storm Events event-days in 4 of 30 years, 1996 to 2025 (13.3%)	161	2000 to 2025 (25.25 years; D3 and D4 only)	countywide
Earthquake	0.00109	annual probability at a location	chance a given location in the county has at least minor-damage shaking in a year: 0.109%			not shown	modeled	see B1-f	No descriptor (Storm Events does not record earthquakes).
Hail	3.78	events per year	about 3.78 per year	Highly likely	FEMA annualized frequency (modeled)	143.6 (modeled)	1986 to 2023 (38 years)	countywide
Heat Wave	4.21	event-days per year	about 4.21 days per year	Likely	Storm Events event-days in 18 of 30 years, 1996 to 2025 (60%)	71	2005-11-12 to 2024-11-12 (19 years)	countywide
Hurricane	0.0888	events per year	about 1 in 11 years	Possible	FEMA annualized frequency (modeled)	32	1851 to 2024 (Atlantic)	see B1-f	NRI counts hurricane and tropical storm tracks passing within storm-force wind range; federal declarations are in B1-d.
Ice Storm	1	event-day per year	about 1 day per year	Likely	Storm Events event-days in 8 of 30 years, 1996 to 2025 (26.7%)	68	1946-12-31 to 2014-02-12 (67 years)	countywide
Inland Flooding	4.68	event-days per year	about 4.68 days per year	Likely	Storm Events event-days in 26 of 30 years, 1996 to 2025 (86.7%)	131	1996 to 2023 (28 years)	see B1-f
Landslide	0.606	events per year (modeled)	about 0.61 per year	Likely	FEMA annualized frequency (modeled)	not shown	modeled	see B1-f
Lightning	37.3	days per year with a strike	about 37.3 days per year	Highly likely	FEMA annualized frequency (modeled)	not shown	1995 to 2023 (29 years; CONUS)	countywide
Strong Wind	7.7	events per year	about 7.7 per year	Highly likely	FEMA annualized frequency (modeled)	293	1986 to 2023 (38 years)	countywide
Tornado	0.453	events per year	about 1 in 2 years	Likely	FEMA annualized frequency (modeled)	not shown	1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)	see B1-f
Wildfire	0.0000718	annual probability at a location	chance a given location in the county burns in a year: 0.00718%		Storm Events records in 0 of 30 years, 1996 to 2025 (0%)	not shown	modeled	see B1-f	No descriptor: no Storm Events record 1996 to 2025
Winter Weather	14.3	event-days per year	about 14.3 days per year	Highly likely	Storm Events event-days in 30 of 30 years, 1996 to 2025 (100%)	272	2005-11-12 to 2024-11-12 (19 years)	countywide

FEMA annualized frequency (modeled) is the National Risk Index v1.20 (December 2025) estimate of how often a hazard affects this county in a year; it is not recorded events divided by years, and its unit differs by hazard (events, event-days, or days with a lightning strike per year). For earthquake, wildfire, coastal flooding and tsunami the value is the chance (or number of events) at a location in the county, not across the county, so no "1 in N years" is given and the descriptor comes from Storm Events where it has a record (none for earthquake). The Methods page gives each hazard's method, from FEMA's National Risk Index Technical Documentation v1.20.

Where NRI gives event-days, the descriptor comes from the share of years with a Storm Events record; NRI's source records more events, so the two differ.

Descriptor scale used in this packet (defined per unit)

Sources: 5, 6

Unit	Descriptor	Definition
events per year	Highly likely	1 or more per year
events per year	Likely	about once in 1 to 10 years
events per year	Possible	about once in 10 to 100 years
events per year	Unlikely	less than once in 100 years
annual probability	Likely	10% to under 100% chance in a given year
annual probability	Possible	1% to under 10% chance in a given year
annual probability	Unlikely	under 1% chance in a given year
event-days (share of years)	Highly likely	event-days recorded in 90% or more of years
event-days (share of years)	Likely	event-days recorded in 10% to under 90% of years
event-days (share of years)	Possible	event-days recorded in some years but under 10% of years
lightning strike-days	Highly likely	cloud-to-ground strikes on 1 or more days per year

Intensity bands: historical frequency (Storm Events)

Source: 6

Hazard	Band	Years	Eventscounty-coded records	Years in period	Events per yearevents / years
Hail	1.00-1.99 in	1996 to 2025	47	30	1.57
Hail	2.00 in+	1996 to 2025	2	30	0.0667
Thunderstorm Wind (counted as NRI Strong Wind)	50-64 kt	1996 to 2025	471	30	15.7
Thunderstorm Wind (counted as NRI Strong Wind)	65 kt+	1996 to 2025	15	30	0.5
Thunderstorm Wind (counted as NRI Strong Wind)	unmeasured or below 50 kt	1996 to 2025	51	30	1.7
Tornado	EF0-1	1996 to 2025	21	30	0.7
Tornado	EF2-3	1996 to 2025	1	30	0.0333
Tornado	EF4-5	1996 to 2025	0	30	0
Tornado	unrated (EFU)	1996 to 2025	0	30	0

The bands show how often events of each severity were recorded in this county, to profile how severe events have been (FEMA's probability item asks for the range of intensities).

Hail smaller than 1 inch is not counted: on 2010-01-05 the National Weather Service raised its severe-hail threshold from 3/4 inch to 1 inch, so smaller reports became less common after 2009 (NWS Service Change Notice 09-52). NRI hail frequency uses a 0.75 inch threshold.

Optional: future conditions. Not a required item in the 2025 FEMA Local Mitigation Planning Policy Guide; some states ask for it. The federal Climate Mapping for Resilience and Adaptation (CMRA) site gives county exposure to future climate conditions (https://resilience.climate.gov/).

Supports FEMA checklist item B1-f: hazards that vary across jurisdictions

Range of census tract risk within the county

Source: 5

Hazard	Tractsrated of all	NRI risk score, 0 to 100			Tracts by rating
Hazard	Tractsrated of all	Min	Median	Max	Tracts by rating
Avalanche	5 of 65	9.4	11.3	12.1	Very Low 5, Not Applicable 60
Cold Wave	65 of 65	17.8	22.7	38.5	Relatively Low 61, Very Low 4
Drought	56 of 65	67.4	83.8	96.3	Relatively Moderate 8, Relatively Low 32, Very Low 16, No Rating 9
Earthquake	65 of 65	15.3	35.2	70.6	Relatively Low 21, Very Low 44
Hail	65 of 65	37.8	59.7	81.2	Relatively Moderate 7, Relatively Low 58
Heat Wave	65 of 65	17.3	50.2	80.1	Relatively Moderate 19, Relatively Low 46
Hurricane	65 of 65	49.8	60.7	77.6	Relatively Low 63, Very Low 2
Ice Storm	65 of 65	6.8	24.5	48.7	Relatively Low 14, Very Low 51
Inland Flooding	65 of 65	1.2	25.0	86.5	Relatively High 2, Relatively Moderate 10, Relatively Low 37, Very Low 16
Landslide	65 of 65	9.7	65.4	92.5	Relatively Low 16, Very Low 49
Lightning	65 of 65	27.9	58.4	87.6	Relatively High 3, Relatively Moderate 45, Relatively Low 17
Strong Wind	65 of 65	31.0	61.5	83.1	Relatively High 1, Relatively Moderate 46, Relatively Low 18
Tornado	65 of 65	26.7	42.5	60.7	Relatively Moderate 3, Relatively Low 59, Very Low 3
Wildfire	63 of 65	19.5	38.7	77.3	Relatively Low 2, Very Low 61, No Rating 2
Winter Weather	65 of 65	50.0	77.2	93.1	Relatively High 27, Relatively Moderate 38

Drought: Agriculture is all of NRI's expected annual loss for this hazard in the county, so the tract range mostly reflects where crop and livestock value is.

Rated tracts only: No Rating (score 0.0), Not Applicable and Insufficient Data tracts are counted but not used for the minimum, median and maximum.

The score ranks a tract against all U.S. tracts (100 = highest). The rating is FEMA's category for the tract's risk value, computed differently, so the two can disagree.

Frequency data for cold wave, drought, hail, heat wave, ice storm, lightning, strong wind and winter weather are county-wide or coarse (49 km grid or NWS zone), the same for every jurisdiction; the tract range mostly reflects where buildings and people are (crop and livestock value where a line above names agriculture).

Each jurisdiction (starting figures from federal data)

Sources: 1, 3, 4, 6

Jurisdiction	Type	Plan status	Repetitive lossFMA RL and SRL (44 CFR 77.2); repeat-flood, any definition	Public Assistance to this jurisdictionFEMA records matched by applicant name; federal share obligated, nominal dollars	Event records naming this placeall years; since its plan	Notes
Frederick County	County	Approved, expires 2027-05-18	FMA RL 0, SRL 5; any 20	$913,441.13	0 total; 0 since its plan	Includes $585,762.36 for declarations not counted as hazard incidents (DR-4491-MD).
Brunswick city	City	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 1	$324,241.29	36 total; 3 since its plan
Burkittsville town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$38,625.77	7 total; 0 since its plan
Emmitsburg town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$48,740.04	47 total; 3 since its plan
Frederick city	City	Approved, expires 2027-05-18	FMA RL 0, SRL 1; any 4	$2,410,138.76	92 total; 13 since its plan
Middletown town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$55,918.95	25 total; 4 since its plan
Mount Airy town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$129,181.82	2 total; 0 since its plan
Myersville town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$172,258.08	24 total; 4 since its plan
New Market town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$21,104.59	21 total; 3 since its plan
Rosemont village	Village	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	no Public Assistance recorded	10 total; 3 since its plan
Thurmont town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$58,218.76	33 total; 3 since its plan
Walkersville town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$61,274.53	28 total; 1 since its plan
Woodsboro town	Town	Approved, expires 2027-05-18	FMA RL 0, SRL 0; any 0	$30,352.10	17 total; 3 since its plan

Repetitive-loss counts are for whole NFIP communities, which can extend beyond this county (see the note in B2-c).

County Public Assistance in B1-d also includes applicants filed under the county that are not jurisdictions in this plan (for example state agencies, special districts and nonprofits), so the jurisdiction rows add up to less.

Supports FEMA checklist items B2-a and B2-b: vulnerability and potential impacts

Local data needed

The table below gives county-level starting figures; the plan describes impacts for each jurisdiction and its own assets.

Critical facilities and lifelines per hazard
A problem statement per jurisdiction per hazard
Changes in development in hazard-prone areas since the last approval, or a statement of none (E1-a)
Future assets

County-level starter: exposure, expected annual loss and damage since the plan

Sources: 1, 2, 3, 5, 6, 7

Hazard	Building exposuremodeled dollars	Agriculture exposuremodeled dollars	Population exposedpeople	EAL buildingsmodeled dollars per year	EAL agriculturemodeled dollars per year	Cost of expected deaths and injuriesFEMA's dollar value per year, not property damage	EAL as % of exposurebuildings; agriculture where noted	Storm Events damage since 2022-05-19county-coded records, property plus crops, nominal dollars	Zone-level damage since planproperty plus crops, reported for the zone	Public Assistance since plannominal dollars; see note	Note
Avalanche	$0	n/a	under 1	$0	n/a	$66					building exposure is 0 in NRI
Cold Wave	$55,998,831,154	$169,431,879	271,433	$73,775	$215,434	$421,186	0.000132%		$0
Drought	n/a	$71,943,474	n/a	n/a	$898,243	n/a	1.25% (agriculture)				NRI has no building exposure for this hazard; agriculture shown
Earthquake	$94,521,594,948	n/a	271,717	$1,323,934	n/a	$367,496	0.0014%
Hail	$55,998,864,278	$169,431,879	271,433	$1,019,637	$36,466	$1,503	0.00182%
Heat Wave	$55,998,831,154	$169,431,879	271,433	under $1	$1,812	$3,097,438	under 0.0001%		$0
Hurricane	$55,992,126,289	$168,865,832	271,384	$1,969,427	$553,749	$80,975	0.00352%
Ice Storm	$55,981,260,908	n/a	271,400	$39,977	n/a	$111,215	under 0.0001%
Inland Flooding	$55,975,145,460	$8,527,216	2,831	$26,535,414	$23,421	$5,677,887	n/a (see note)	$0			NRI counts the full building value of any census block with some flood loss; this is not the value of buildings in the floodplain. Use local FIRM overlays for B2-a/B2-b.
Landslide	$1,979,406,861	n/a	10,571	$6,053	n/a	$591	0.000306%
Lightning	$55,998,864,278	n/a	271,433	$93,342	n/a	$1,135,047	0.000167%
Strong Wind	$55,998,864,278	$169,431,879	271,433	$369,244	$61,612	$1,589,970	0.000659%	$3,103,000	$0
Tornado	$55,998,864,278	$169,431,879	271,433	$1,735,406	$3,981	$1,757,129	0.0031%
Wildfire	$5,065,402,310	$21,130,174	30,656	$15,469	$10	$3,286	0.000305%
Winter Weather	$55,998,831,154	$169,431,879	271,433	$48,799	$61	$596,027	under 0.0001%		$0	no Public Assistance recorded (1 declaration)

Totals since 2022-05-19 (Storm Events through 2026-06-30): 133 county-coded records, 119 with a damage value recorded (including $0), $3,103,000; 36 zone-level records, 16 with a damage value recorded (including $0), $0 reported for the zone; Public Assistance: none recorded on the 1 counted declaration.

FEMA does not split Public Assistance by hazard. A declaration mapped to several hazards is listed under each of them with its full amount, so the per-hazard column does not add up to the total; the unit total counts each declaration once.

NRI computes earthquake exposure on its own basis, so it exceeds the county building value in B2-a.

Supports FEMA checklist item B2-a: vulnerability (county context)

County context

Source: 5

Measure	Value
Population	271,433
Building value (total, not at risk)	$55,998,864,278
Agriculture value (total, not at risk)	$169,431,879
NRI risk rating (all hazards)	Relatively Low
Expected annual loss, buildings and agriculture, all hazards	$35,025,265
Expected annual loss, population equivalence, all hazards (NRI values each statistical life at $13.7M; a modeled value of expected deaths and injuries, not property damage)	$14,839,816
Social vulnerability rating	Very Low
Community resilience rating	Relatively High
NRI version	December 2025

FEMA's all-hazard expected annual loss adds buildings, agriculture and population equivalence; this table gives the property part and the population-equivalence part as separate rows.

Social vulnerability: higher means people are more likely to be harmed and slower to recover. Community resilience: lower means the community is less able to recover. High social vulnerability and low resilience both raise the NRI risk rating.

Supports FEMA checklist item B2-c: repetitive loss properties

Repetitive loss in this county, both definitions

Sources: 1, 4

Definition	Properties	Severe repetitive loss	Properties
Repetitive loss, FMA definition (44 CFR 77.2)	0	Severe repetitive loss, FMA definition (44 CFR 77.2)	6
Repetitive loss, NFIP insurance definition	25	Severe repetitive loss, NFIP insurance definition	6

The state NFIP coordinator's list, the source FEMA's Handbook names, often uses the NFIP insurance definition (second row).

Repeat-flood properties: county total and NFIP communities

Sources: 1, 4

Scope	SRL, FMAproperties	RL, NFIPproperties	SRL, NFIPproperties	Any categoryproperties	Currently insuredproperties
County total	6	25	6	25	2
of which: Frederick County (unincorporated area)	5	20	5	20	1
of which: Brunswick city	0	1	0	1	0
of which: Frederick city	1	4	1	4	1

Repeat-flood properties by jurisdiction in the plan (NFIP community)

Sources: 1, 4

Jurisdiction	NFIP community ID	SRL, FMAproperties	RL, NFIPproperties	SRL, NFIPproperties	Any categoryproperties	Currently insuredproperties
Frederick County	240027	5	20	5	20	1
Brunswick city	240028	0	1	0	1	0
Burkittsville town	240164	0	0	0	0	0
Emmitsburg town	240029	0	0	0	0	0
Frederick city	240030	1	4	1	4	1
Middletown town	240162	0	0	0	0	0
Mount Airy town	240200	0	0	0	0	0
Myersville town	240116	0	0	0	0	0
New Market town	240088	0	0	0	0	0
Rosemont village	240085	0	0	0	0	0
Thurmont town	240031	0	0	0	0	0
Walkersville town	240032	0	0	0	0	0
Woodsboro town	240033	0	0	0	0	0

Counts by occupancy group for each jurisdiction are in the Excel file, sheet "B2-c Jurisdictions".

Jurisdiction rows are whole NFIP communities and need not add up to the county total: a community that extends into another county is counted in full on each jurisdiction row, while the county table counts only its part in this county.

County repeat-flood properties by occupancy group

Sources: 1, 4

Occupancy group	SRL, FMAproperties	RL, NFIPproperties	SRL, NFIPproperties	Any categoryproperties	Currently insuredproperties
single-family residential	5	20	5	20	2
2 to 4 unit residential	0	0	0	0	0
other residential	0	0	0	0	0
non-residential	1	5	1	5	0
not reported	0	0	0	0	0

FEMA's occupancy groups have no institutional class; institutional properties are counted in non-residential or other residential in the table by occupancy group.

FMA RL and FMA SRL are the Flood Mitigation Assistance definitions (44 CFR 77.2), the ones the FEMA Local Mitigation Planning Policy Guide cites. NFIP repetitive loss (the FEMA insurance definition) is 2 or more claims over $1,000 in 10 years, and a property can leave that group once it is mitigated. Also shown: NFIP severe repetitive loss, any category, mitigated and currently insured. The Methods page gives the OpenFEMA field details.

Counts are aggregates of FEMA's public NFIP Multiple Loss Properties file (FEMA's data date 2026-08-02; file version 2026-08-04). No property is identified. County assignment is FEMA's geocode.

In this county 0 properties are FMA repetitive loss but not NFIP repetitive loss, and 25 properties are NFIP repetitive loss but not FMA repetitive loss.

Exact counts; no count suppression.

Sources

Tables cite these sources by number. The full list, for the plan's bibliography (FEMA review item A4-a):

FEMA, OpenFEMA HazardMitigationPlanStatuses v1, version 2026-09-29T134039Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/HazardMitigationPlanStatuses (API)
FEMA, OpenFEMA DisasterDeclarationsSummaries v2, version 2026-09-29T162832Z, pulled 2026-09-30, https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries (API)
FEMA, OpenFEMA PublicAssistanceFundedProjectsSummaries v1, version 2026-09-29T150754Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/PublicAssistanceFundedProjectsSummaries (API)
FEMA, OpenFEMA NfipMultipleLossProperties v1, version 2026-08-04T164045Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/NfipMultipleLossProperties (API)
FEMA, FEMA National Risk Index 1.20.0 (December 2025), county and census tract tables, version 1.20.0, pulled 2026-09-30, https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_Counties.zip (download, 25 MB), https://www.fema.gov/about/reports-and-data/openfema/nri/v120/NRI_Table_CensusTracts.zip (download, 635 MB)
NOAA NCEI, NOAA NCEI Storm Events Database, details files (csvfiles v1.0), version c20260918, pulled 2026-09-30, https://www.ncei.noaa.gov/pub/data/swdi/stormevents/csvfiles/
NOAA National Weather Service, NWS county-public forecast zones correlation file, version bp03mr20 to bp16ap26 (11 files; newest bp16ap26), pulled 2026-09-30, https://www.weather.gov/gis/ZoneCounty
U.S. Census Bureau, Census 2024 Gazetteer, 2020 place by county, CT county-to-cousub crosswalk, version 2024-gazetteer, pulled 2026-09-30, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_counties_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_cousubs_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_place_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_unsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_elsd_national.zip, https://www2.census.gov/geo/docs/maps-data/data/gazetteer/2024_Gazetteer/2024_Gaz_scsd_national.zip, https://www2.census.gov/geo/docs/reference/codes2020/national_place_by_county2020.txt, https://www2.census.gov/geo/docs/reference/ct_change/ct_cou_to_cousub_crosswalk.xlsx (used to match place names and codes; no table prints its values)

What this packet is and what the plan adds

This packet is the federal data for the plan's risk assessment (the summary on page 1 says how it is organized); the plan and FEMA's review decide whether each item is met.

The plan adds what only the community has: local data on assets, critical facilities, development and each jurisdiction's impacts; local hazard history, including state-declared emergencies; the mitigation strategy; and adoption.

How the federal data are built: National Risk Index values are FEMA's model, not counts of events. Storm Events is more complete from 1996; zone-level records are placed by forecast zone, not by location in the county. Public Assistance for a jurisdiction is matched by applicant name. The Methods page gives every rule and the known edge cases.

OpenFEMA disclaimer

This product uses the Federal Emergency Management Agency's OpenFEMA API, but is not endorsed by FEMA. The Federal Government or FEMA cannot vouch for the data or analyses derived from these data after the data have been retrieved from the Agency's website(s).

Reuse, citation and corrections

Reuse and citation: Hazard Plain text and tables are licensed under Creative Commons Attribution 4.0 International (CC BY 4.0, https://creativecommons.org/licenses/by/4.0/); credit Hazard Plain and the release. The underlying federal data are public domain; OpenFEMA data are also subject to the OpenFEMA terms and conditions.

Cite this: Hazard Plain (2026). Frederick County, MD: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 24021). Automated baseline. https://hazardplain.org/md/24021/ Built from FEMA OpenFEMA, the FEMA National Risk Index and NOAA NCEI Storm Events; source versions in the packet's Sources list.

Corrections: to report an error, name the packet, the table and what your records show. Contact: [email protected]