Summary
Plan status as of 2026-09-30: Approved, expires 2031-06-03. Plan: City of Philadelphia Hazard Mitigation Plan (FEMA plan 110755), approved 2026-06-04.
Since the plan was approved on 2026-06-04: no new hazard declaration and 17 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 ($266,057,136 a year), Heat Wave ($256,419,434) and Cold Wave ($57,040,490).
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.
Plan clock
- Status:
- Approved, expires 2031-06-03
- Plan:
- City of Philadelphia Hazard Mitigation Plan (FEMA plan 110755)
- Approved:
- 2026-06-04
- Days to expiry:
- 1,707
Also approved under plan 108236 (City of Philadelphia Hazard Mitigation Plan, expires 2027-05-18). FEMA's plan status map shows one plan per jurisdiction and may show one of these; this packet uses the approved plan that expires last.
Plan clock from the consolidated city-county government plan (Philadelphia city). FEMA plan data has no separate county-level row for this county.
What changed since your last plan (approved 2026-06-04)
- New federal declarations:
- none
- Storm Events records since approval:
- 17 records (data through 2026-06-30)
- Repetitive loss now:
- FMA RL 4, SRL 35 (44 CFR 77.2); any definition: 142
- 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
Source: 1
| Jurisdiction | Type | Status | Plan | Approved | Expires | Days to expirynegative = days since expiry | Notes |
|---|---|---|---|---|---|---|---|
| Philadelphia city | City | Approved, expires 2031-06-03 | City of Philadelphia Hazard Mitigation Plan (FEMA plan 110755) | 2026-06-04 | 2031-06-03 | 1,707 | Also approved under plan 108236 (City of Philadelphia Hazard Mitigation Plan, expires 2027-05-18). FEMA's plan status map shows one plan per jurisdiction and may show one of these; this packet uses the approved plan that expires last. |
State plan status and tribal plans in this state: see the state page.
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 | Very High | Relatively High | $262,808,562 | $565 | $3,248,009 | $266,057,136 | 246 | |
| 2 | Heat Wave | Very High | Very High | $1,316 | $10 | $256,418,109 | $256,419,434 | 137 | |
| 3 | Cold Wave | Very High | Very High | $12,115 | under $1 | $57,028,375 | $57,040,490 | 33 | Includes 1 Frost/Freeze record (outside NRI's Cold Wave definition; counted in this table and in B1-d, not in the B1-e descriptor). |
| 4 | Earthquake | Relatively High | Relatively High | $24,823,117 | n/a | $16,806,461 | $41,629,578 | Storm Events does not record earthquakes. | |
| 5 | Tornado | Relatively High | Relatively High | $6,605,994 | $5 | $14,496,551 | $21,102,550 | 6 | |
| 6 | Hurricane | Relatively High | Relatively High | $11,522,453 | $1,537 | $496,730 | $12,020,719 | 3 | |
| 7 | Strong Wind | Relatively High | Relatively High | $640,350 | $1 | $2,860,443 | $3,500,793 | 427 | Includes 41 High Wind and 104 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition). |
| 8 | Coastal Flooding | Relatively High | Relatively High | $2,618,897 | n/a | $182,935 | $2,801,833 | 58 | |
| 9 | Hail | Relatively High | Relatively Moderate | $2,003,804 | $144 | $51,189 | $2,055,138 | 37 | |
| 10 | Winter Weather | Very High | Very High | $192,166 | under $1 | $1,743,016 | $1,935,182 | 207 | Includes 5 Sleet records (outside NRI's Winter Weather definition). |
| 11 | Lightning | Relatively High | Relatively High | $12,252 | n/a | $1,488,047 | $1,500,298 | 11 | |
| 12 | Ice Storm | Relatively High | Relatively High | $411,084 | n/a | $577,669 | $988,753 | 2 | |
| 13 | Wildfire | Very Low | Very Low | $7,330 | under $1 | $1,474 | $8,805 | 1 | |
| 14 | Landslide | Relatively Low | Very Low | $7,158 | n/a | $9 | $7,168 | 0 | No recorded events in Storm Events since 1996 (data through 2026-06-30). |
| 15 | Drought | Very Low | Very Low | n/a | $4,120 | n/a | $4,120 | 46 | |
| Tsunami | Insufficient Data | Insufficient Data | n/a | n/a | n/a | n/a | 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 landslide and tsunami 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: avalanche 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.
Coastal Flooding and 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 |
|---|---|
| Earthquake | tract 153 (Relatively Moderate, 88.0); tract 191 (Relatively Moderate, 84.3); tract 330 (Relatively Moderate, 83.8) |
| Hurricane | tract 369.02 (Relatively Moderate, 87.2); tract 153 (Relatively Moderate, 84.4); tract 4.04 (Relatively Low, 78.0) |
| Landslide | tract 386 (Relatively Low, 93.0); tract 220 (Relatively Low, 91.6); tract 216 (Relatively Low, 89.7) |
| Tornado | tract 369.02 (Relatively High, 81.5); tract 153 (Relatively High, 77.4); tract 355 (Relatively Moderate, 69.4) |
| Tsunami | no tract has a National Risk Index rating for this hazard |
| Wildfire | tract 352 (Relatively Low, 73.4); tract 122.04 (Relatively Low, 72.9); tract 362.01 (Very Low, 64.4) |
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 153 is Census Tract 153). 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 |
|---|---|---|---|---|---|---|---|
| Coastal Flood, Storm Surge/Tide | none in data (flood depth: FIRM) | 58 records, 1996 to 2024 (58 zone-level) | Coastal Flood, 2011-04-16, $100,000 property; $0 crops (2011 dollars); NWS zone PAZ071 | Countywide (zone-level records). | Flood depth: see the FEMA Flood Insurance Rate Map. | ||
| Cold/Wind Chill, Extreme Cold/Wind Chill | wind chill | 32 records, 1996 to 2022 (32 zone-level) | 1 day to 16 days (median 1 day); 27 with a recorded value | 16 consecutive days, 2003-01-14 to 2003-01-29, 3 direct deaths, zone-level | Cold/Wind Chill, 2015-02-20, $250,000 property; $0 crops (zone total, 2015 dollars) | Countywide (zone-level records). | Cold/Wind Chill records from May to September (a frost night, not a cold wave) are counted but not used for the longest run. |
| Frost/Freeze (outside NRI's Cold Wave definition) | crop damage | 1 record, 2007 (1 zone-level) | No crop damage reported in 1 record. | Countywide (zone-level records). | |||
| Drought | U.S. Drought Monitor scale (D0 to D4) | 46 records, 1997 to 2010 (46 zone-level) | 1 day to 385 days (median 11 days); 18 with a recorded value | 385 days (about 12.6 months), 2001-11-06 to 2002-11-25, a run of 15 consecutive Storm Events drought records, zone-level | 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) | 45 records, 1978 to 2023 | 0.75 in to 1.75 in (median 0.88 in); 45 with a recorded value | 1.75 in hail, 2009-03-29; same size also recorded on 1978-08-11, 1994-06-29, 1995-05-29, 2006-08-25 | Event records naming jurisdictions in the plan: Philadelphia city (18 records). | ||
| Excessive Heat, Heat | heat index (in event narratives) | 137 records, 1996 to 2026 (137 zone-level) | 1 day to 10 days (median 2 days); 111 with a recorded value | 10 consecutive days, 2002-08-11 to 2002-08-20, 8 direct deaths, zone-level | Excessive Heat, 2011-06-08, $25,000 property; $0 crops (zone total, 2011 dollars) | 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 | 3 records, 2008 to 2020 (3 zone-level) | Strongest recorded: Tropical Storm record, 2011-08-27 to 2011-08-28, $10,000 property; $0 crops (2011 dollars); NWS zone PAZ071 | 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) | 2 records, 2011 to 2014 (2 zone-level) | No damage reported in 2 records. | Countywide (zone-level records). | |||
| Flash Flood, Flood, Lakeshore Flood | damage and flood days (flood depth: FIRM) | 246 records, 1996 to 2026 (20 zone-level) | Flash Flood, 2021-09-01, $60,000,000 property; $0 crops (2021 dollars) | Event records naming jurisdictions in the plan: Philadelphia city (34 records). Zone-level records (20) 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) | 11 records, 1999 to 2014 | Lightning, 2009-08-02, $100,000 property; $0 crops (2009 dollars) | Event records naming jurisdictions in the plan: Philadelphia city (5 records). | Storm Events lists lightning with damage or casualties. | ||
| High Wind and Strong Wind (outside NRI's Strong Wind definition) | wind speed (kt and mph) | 145 records, 1996 to 2026 (145 zone-level) | 29 kt (33 mph) to 61 kt (70 mph) (median 42 kt (48 mph)); 116 with a recorded value | 61 kt (70 mph) measured gust, High Wind, 2012-10-29; NWS zone PAZ071 | High Wind, 2003-09-18, $3,020,000 property; crops not reported (zone total, 2003 dollars) | Countywide (zone-level records). | |
| Thunderstorm Wind | wind speed (kt and mph) | 339 records, 1969 to 2026 | 43 kt (49 mph) to 87 kt (100 mph) (median 51 kt (59 mph)); 299 with a recorded value | 87 kt (100 mph), measurement type not recorded, Thunderstorm Wind, 1992-08-11 | Thunderstorm Wind, 1994-06-19, $5,000,000 property; crops not recorded (1994 dollars) | Event records naming jurisdictions in the plan: Philadelphia city (78 records). | |
| Tornado | Enhanced Fujita (Fujita before Feb 2007) | 12 records, 1958 to 2021 | F/EF0 to F/EF3 (median between F/EF1 and F/EF2); 12 with a recorded value | EF3 tornado, 2021-07-29, 0.62 mi within this county, 530 yd wide, property not reported; $0 crops (2021 dollars) | Tornado, 1991-08-03, $2,500,000 property; crops not recorded (1991 dollars) | Event records naming jurisdictions in the plan: Philadelphia city (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). |
| Tsunami | none (count and damage only) | 0 | |||||
| Wildfire | acres burned (local data) | 1 record, 2002 (1 zone-level) | No damage reported in 1 record. | Countywide (zone-level records). | |||
| Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleet | none in data (snowfall: local data) | 207 records, 1996 to 2026 (207 zone-level) | Winter Storm, 2003-02-16, $4,000,000 property; crops not reported (2003 dollars), 2 direct deaths, 1 direct injury (reported for the zone); NWS zone PAZ071 | Countywide (zone-level records). |
In event narratives only (local data needed): wind chill, temperature, heat index, ice thickness, acres burned and snow depth; any physical measure of debris flow, lightning and tsunami.
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: 25 declarations covering 18 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 | Notes |
|---|---|---|---|---|---|---|---|
| 2021-09-10 | 2021-08-31 | DR-4618-PA | Major disaster | Remnants of Hurricane Ida | Hurricane | $6,369,013.81 | |
| 2020-03-30 | 2020-01-20 | DR-4506-PA | Major disaster | COVID-19 Pandemic | Non-natural, not counted | $207,580,025.47 | |
| 2020-03-13 | 2020-01-20 | EM-3441-PA | Emergency | COVID-19 | Non-natural, not counted | no Public Assistance recorded | same incident as DR-4506 |
| 2016-03-23 | 2016-01-22 | DR-4267-PA | Major disaster | Severe Winter Storm and Snowstorm | Winter Weather | $7,727,794.43 | |
| 2014-02-06 | 2014-02-04 | EM-3367-PA | Emergency | Severe Winter Storm | Ice Storm | no Public Assistance recorded | |
| 2013-01-10 | 2012-10-26 | DR-4099-PA | Major disaster | Hurricane Sandy | Hurricane | $2,233,706.80 | |
| 2012-10-29 | 2012-10-26 | EM-3356-PA | Emergency | Hurricane Sandy | Hurricane | no Public Assistance recorded | same incident as DR-4099 |
| 2011-09-12 | 2011-09-03 | DR-4030-PA | Major disaster | Tropical Storm Lee | Inland Flooding (primary); also designated: Hurricane | $141,597.24 | FEMA's declaration record does not list Public Assistance, but FEMA's PA project summaries show obligations for this county |
| 2011-09-08 | 2011-09-03 | EM-3340-PA | Emergency | Remnants of Tropical Storm Lee | Inland Flooding (primary); also designated: Hurricane | $301,818.34 | same incident as DR-4030 |
| 2011-09-03 | 2011-08-26 | DR-4025-PA | Major disaster | Hurricane Irene | Hurricane | $4,775,537.27 | |
| 2011-08-29 | 2011-08-26 | EM-3339-PA | Emergency | Hurricane Irene | Hurricane | no Public Assistance recorded | same incident as DR-4025 |
| 2010-04-16 | 2010-02-05 | DR-1898-PA | Major disaster | Severe Winter Storms and Snowstorms | Winter Weather | $7,476,703.74 | |
| 2005-09-10 | 2005-08-29 | EM-3235-PA | Emergency | Hurricane Katrina | Hurricane: evacuation support, not a local hazard event; not counted | $3,120,197.10 | |
| 2004-09-19 | 2004-09-17 | DR-1557-PA | Major disaster | Tropical Depression Ivan | Hurricane | PA not declared for this county | |
| 2004-09-19 | 2004-09-08 | DR-1555-PA | Major disaster | Severe Storms and Flooding Associated with Tropical Depression Frances | Hurricane; Inland Flooding: designated for Hazard Mitigation only (no Public or Individual Assistance for this county); not counted | PA not declared for this county | |
| 2004-08-06 | 2004-07-27 | DR-1538-PA | Major disaster | Severe Storms and Flooding | Inland Flooding | PA not declared for this county | |
| 2003-03-14 | 2003-02-14 | EM-3180-PA | Emergency | Snow | Winter Weather | $4,832,498.94 | |
| 1999-09-18 | 1999-09-16 | DR-1294-PA | Major disaster | Hurricane Floyd Major Disaster Declarations | Hurricane | $1,511,337.51 | |
| 1996-01-21 | 1996-01-19 | DR-1093-PA | Major disaster | Severe Storms and Flooding | Inland Flooding | PA not declared for this county | |
| 1996-01-13 | 1996-01-06 | DR-1085-PA | Major disaster | Blizzard of 96 | Winter Weather | no Public Assistance recorded | |
| 1994-03-10 | 1994-01-04 | DR-1015-PA | Major disaster | Severe Winter Storms | Winter Weather | no Public Assistance recorded | |
| 1993-03-16 | 1993-03-13 | EM-3105-PA | Emergency | Severe Snowfall & Winter Storm | Winter Weather | no Public Assistance recorded | |
| 1972-06-23 | 1972-06-23 | DR-340-PA | Major disaster | Tropical Storm Agnes | Inland Flooding (primary); also designated: Hurricane | no Public Assistance recorded | |
| 1971-09-18 | 1971-09-18 | DR-312-PA | Major disaster | Floods | Inland Flooding | no Public Assistance recorded | |
| 1965-08-18 | 1965-08-18 | DR-206-PA | Major disaster | Water Shortage | Drought | 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 |
|---|---|---|---|---|---|
| 2003-08-23 | 2003-07-21 | DR-1485-PA | Major disaster | Severe Storms, Tornadoes, and Flooding | Inland Flooding; Tornado |
| 1959-01-23 | 1959-01-23 | DR-89-PA | Major disaster | Floods | Inland Flooding |
| 1956-08-09 | 1956-08-09 | DR-61-PA | Major disaster | Storm | Hazard not mapped (severe storm title names no single hazard); not counted |
| 1956-05-21 | 1956-05-21 | DR-58-PA | Major disaster | Severe Storm | Hazard not mapped (severe storm title names no single hazard); not counted |
| 1956-03-15 | 1956-03-15 | DR-51-PA | Major disaster | Flood | Inland Flooding |
| 1955-08-20 | 1955-08-20 | DR-40-PA | Major disaster | Floods & Rains | Inland 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, $4,317,276.81
Sources: 2, 3
| FEMA number | Declared | Title | Applicant | PA obligatedfederal share obligated, nominal dollars |
|---|---|---|---|---|
| DR-1383-PA | 2001-06-21 | Tropical Storm Allison | Southeastern Pennsylvania Transportation Authority (Philadelphia County) | $4,317,276.81 |
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.
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 |
|---|---|---|---|---|---|---|---|---|
| Coastal Flooding | 58 | 0 | 0 | 10 | 0 | 0 | 1996 to 2026-06-30 | |
| Cold Wave | 33 | 0 | 0 | 1 | 0 | 0 | 1996 to 2026-06-30 | Includes 1 Frost/Freeze record. |
| Drought | 46 | 0 | 0 | 0 | 1 | 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 | 45 | 0 | 0 | 6 | 0 | 0 | 1955 to 2026-06-30 | |
| Heat Wave | 137 | 1 | 5 | 13 | 0 | 0 | 1996 to 2026-06-30 | |
| Hurricane | 3 | 0 | 0 | 0 | 7 | 0 | 1996 to 2026-06-30 | |
| Ice Storm | 2 | 0 | 0 | 0 | 1 | 0 | 1996 to 2026-06-30 | |
| Inland Flooding | 246 | 6 | 13 | 37 | 5 | 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 | 11 | 0 | 0 | 0 | 0 | 0 | 1996 to 2026-06-30 | |
| Strong Wind | 484 | 10 | 17 | 65 | 0 | 0 | 1955 to 2026-06-30 | Includes 41 High Wind and 104 Strong Wind records. |
| Tornado | 12 | 0 | 0 | 0 | 0 | 0 | 1950 to 2026-06-30 | |
| Tsunami | 0 | 0 | 0 | 0 | 0 | 0 | 1996 to 2026-06-30 | No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events |
| Wildfire | 1 | 0 | 0 | 0 | 0 | 0 | 1996 to 2026-06-30 | |
| Winter Weather | 207 | 0 | 7 | 24 | 6 | 0 | 1996 to 2026-06-30 | Includes 5 Sleet records. |
Notable Storm Events records
Sources: 1, 6, 7
| Date | Event type | Magnitude or extent | Damagenominal dollars | Deaths, injuriesdirect only | Location | Why listed |
|---|---|---|---|---|---|---|
| 2021-09-01 | Flash Flood | $60,000,000 property; $0 crops (2021 dollars) | 0, 0 | WAYNE JCT to ROXBOROUGH | B1-c worst recorded: Flash Flood, Flood, Lakeshore Flood | |
| 2021-07-29 | Tornado | EF3, 0.62 mi within this county, 530 yd wide | property not reported; $0 crops (2021 dollars) | 0, 0 | BYBERRY | B1-c worst recorded: Tornado |
| 2012-10-29 | High Wind | 61 kt (70 mph) measured gust | $400,000 property; $0 crops (zone total, 2012 dollars) | 0, 0 | NWS zone PAZ071 (PHILADELPHIA), zone-level | B1-c worst recorded: High Wind and Strong Wind |
| 2011-08-27 | Tropical Storm | $10,000 property; $0 crops (zone total, 2011 dollars) | 0, 0 | NWS zone PAZ071 (PHILADELPHIA), zone-level | B1-c worst recorded: Hurricane, Tropical Storm, Tropical Depression | |
| 2011-07-21 | Excessive Heat | $0 property; $0 crops (zone total, 2011 dollars) | 22, 48 | NWS zone PAZ071 (PHILADELPHIA), zone-level | deaths or injuries recorded | |
| 2011-04-16 | Coastal Flood | $100,000 property; $0 crops (zone total, 2011 dollars) | 0, 0 | NWS zone PAZ071 (PHILADELPHIA), zone-level | B1-c worst recorded: Coastal Flood, Storm Surge/Tide | |
| 2009-03-29 | Hail | 1.75 in | $0 property; $0 crops (2009 dollars) | 0, 0 | TORRESDALE | B1-c worst recorded: Hail |
| 2003-01-14 | Cold/Wind Chill | damage not reported | 3, 0 | NWS zone PAZ071 (PHILADELPHIA), zone-level | B1-c worst recorded: Cold/Wind Chill, Extreme Cold/Wind Chill | |
| 2002-08-11 | Heat | damage not reported | 8, 0 | NWS zone PAZ071 (PHILADELPHIA), zone-level | B1-c worst recorded: Excessive Heat, Heat | |
| 1999-07-04 | Heat | damage not reported | 58, 124 | NWS zone PAZ071 (PHILADELPHIA), zone-level | deaths or injuries recorded | |
| 1997-07-12 | Heat | damage not reported | 23, 50 | NWS zone PAZ071 (PHILADELPHIA), zone-level | deaths or injuries recorded | |
| 1992-08-11 | Thunderstorm Wind | 87 kt (100 mph), measurement type not recorded | damage not recorded (pre-1996 record) | 0, 0 | location not recorded | B1-c worst recorded: Thunderstorm Wind |
The full list is in the Excel file, sheet "B1-d Storm Events history" (1,285 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 |
|---|---|---|---|---|---|---|---|---|---|
| Coastal Flooding | 3.69 | events per year at a location (modeled) | about 3.7 per year at a given location in the county | Highly likely | FEMA annualized frequency (modeled) | not shown | modeled | see B1-f | Descriptor from NRI: the rate at a location is 1 or more a year, so the county rate is at least that. |
| Cold Wave | 0.791 | event-days per year | about 0.791 days per year | Likely | Storm Events event-days in 13 of 30 years, 1996 to 2025 (43.3%) | 15 | 2005-11-12 to 2024-11-12 (19 years) | countywide | |
| Drought | 5.76 | event-days per year | about 5.76 days per year | Likely | Storm Events event-days in 10 of 30 years, 1996 to 2025 (33.3%) | 161 | 2000 to 2025 (25.25 years; D3 and D4 only) | countywide | |
| Earthquake | 0.00162 | annual probability at a location | chance a given location in the county has at least minor-damage shaking in a year: 0.162% | not shown | modeled | see B1-f | No descriptor (Storm Events does not record earthquakes). | ||
| Hail | 2.51 | events per year | about 2.51 per year | Highly likely | FEMA annualized frequency (modeled) | 95.4 (modeled) | 1986 to 2023 (38 years) | countywide | |
| Heat Wave | 11.1 | event-days per year | about 11.1 days per year | Highly likely | Storm Events event-days in 27 of 30 years, 1996 to 2025 (90%) | 125 | 2005-11-12 to 2024-11-12 (19 years) | countywide | |
| Hurricane | 0.092 | events per year | about 1 in 11 years | Possible | FEMA annualized frequency (modeled) | 16 | 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 | 1.44 | event-days per year | about 1.44 days per year | Possible | Storm Events event-days in 2 of 30 years, 1996 to 2025 (6.67%) | 97 | 1946-12-31 to 2014-02-12 (67 years) | countywide | |
| Inland Flooding | 5.82 | event-days per year | about 5.82 days per year | Highly likely | Storm Events event-days in 30 of 30 years, 1996 to 2025 (100%) | 163 | 1996 to 2023 (28 years) | see B1-f | |
| Landslide | 0.0578 | events per year (modeled) | about 1 in 17 years | Possible | FEMA annualized frequency (modeled) | not shown | modeled | see B1-f | |
| Lightning | 35.7 | days per year with a strike | about 35.7 days per year | Highly likely | FEMA annualized frequency (modeled) | not shown | 1995 to 2023 (29 years; CONUS) | countywide | |
| Strong Wind | 7.04 | events per year | about 7.04 per year | Highly likely | FEMA annualized frequency (modeled) | 268 | 1986 to 2023 (38 years) | countywide | |
| Tornado | 0.073 | events per year | about 1 in 14 years | Possible | FEMA annualized frequency (modeled) | not shown | 1950 to 2023 (EF2+); 1986 to 2023 (EF0-1) | see B1-f | |
| Tsunami | annual probability at the most exposed location (used in place of a county value) | 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 | |||
| Wildfire | 0.0000915 | annual probability at a location | chance a given location in the county burns in a year: 0.00915% | Possible | Storm Events records in 1 of 30 years, 1996 to 2025 (3.33%) | not shown | modeled | see B1-f | |
| Winter Weather | 10.5 | event-days per year | about 10.5 days per year | Highly likely | Storm Events event-days in 29 of 30 years, 1996 to 2025 (96.7%) | 200 | 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 | 15 | 30 | 0.5 |
| Hail | 2.00 in+ | 1996 to 2025 | 0 | 30 | 0 |
| Thunderstorm Wind (counted as NRI Strong Wind) | 50-64 kt | 1996 to 2025 | 260 | 30 | 8.67 |
| Thunderstorm Wind (counted as NRI Strong Wind) | 65 kt+ | 1996 to 2025 | 1 | 30 | 0.0333 |
| Thunderstorm Wind (counted as NRI Strong Wind) | unmeasured or below 50 kt | 1996 to 2025 | 7 | 30 | 0.233 |
| Tornado | EF0-1 | 1996 to 2025 | 3 | 30 | 0.1 |
| Tornado | EF2-3 | 1996 to 2025 | 3 | 30 | 0.1 |
| 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 | ||
|---|---|---|---|---|---|
| Min | Median | Max | |||
| Coastal Flooding | 35 of 408 | 69.7 | 85.7 | 98.8 | Relatively High 9, Relatively Moderate 7, Relatively Low 13, Very Low 6, No Rating 373 |
| Cold Wave | 408 of 408 | 15.5 | 79.5 | 94.6 | Relatively High 230, Relatively Moderate 153, Relatively Low 5, Very Low 20 |
| Drought | 18 of 408 | 66.9 | 72.3 | 83.6 | Relatively Low 1, Very Low 17, No Rating 390 |
| Earthquake | 408 of 408 | 2.0 | 75.4 | 88.0 | Relatively Moderate 145, Relatively Low 242, Very Low 21 |
| Hail | 408 of 408 | 1.1 | 45.8 | 84.8 | Relatively Moderate 2, Relatively Low 353, Very Low 53 |
| Heat Wave | 408 of 408 | 1.4 | 98.1 | 99.9 | Very High 324, Relatively High 62, Relatively Moderate 2, Very Low 20 |
| Hurricane | 408 of 408 | 22.1 | 62.5 | 87.2 | Relatively Moderate 2, Relatively Low 393, Very Low 13 |
| Ice Storm | 408 of 408 | 0.1 | 36.1 | 78.3 | Relatively Moderate 2, Relatively Low 235, Very Low 171 |
| Inland Flooding | 408 of 408 | 0.2 | 53.8 | 99.4 | Very High 9, Relatively High 71, Relatively Moderate 159, Relatively Low 136, Very Low 33 |
| Landslide | 363 of 408 | 8.6 | 47.2 | 93.0 | Relatively Low 16, Very Low 347, No Rating 45 |
| Lightning | 408 of 408 | 0.1 | 25.6 | 50.6 | Relatively Moderate 5, Relatively Low 273, Very Low 130 |
| Strong Wind | 408 of 408 | 0.3 | 37.6 | 68.6 | Relatively Moderate 20, Relatively Low 357, Very Low 31 |
| Tornado | 408 of 408 | 1.0 | 49.8 | 81.5 | Relatively High 2, Relatively Moderate 126, Relatively Low 264, Very Low 16 |
| Tsunami | 0 of 408 | Insufficient Data 408 | |||
| Wildfire | 73 of 408 | 18.5 | 28.1 | 73.4 | Relatively Low 2, Very Low 71, No Rating 335 |
| Winter Weather | 408 of 408 | 10.9 | 69.5 | 89.2 | Relatively High 63, Relatively Moderate 310, Relatively Low 23, Very Low 12 |
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 |
|---|---|---|---|---|---|---|
| Philadelphia city | City | Approved, expires 2031-06-03 | FMA RL 4, SRL 35; any 133 | $133,215,869.44 | 136 total; 0 since its plan | Also approved under plan 108236 (City of Philadelphia Hazard Mitigation Plan, expires 2027-05-18). FEMA's plan status map shows one plan per jurisdiction and may show one of these; this packet uses the approved plan that expires last. Includes $110,446,459 for declarations not counted as hazard incidents (DR-4506-PA, EM-3235-PA). |
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 2026-06-04county-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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Coastal Flooding | $12,325,731,508 | n/a | 28,116 | $2,618,897 | n/a | $182,935 | 0.0212% | ||||
| Cold Wave | $291,673,614,404 | $421,121 | 1,602,305 | $12,115 | under $1 | $57,028,375 | under 0.0001% | ||||
| Drought | n/a | $340,906 | n/a | n/a | $4,120 | n/a | 1.21% (agriculture) | NRI has no building exposure for this hazard; agriculture shown | |||
| Earthquake | $516,179,828,672 | n/a | 1,603,797 | $24,823,117 | n/a | $16,806,461 | 0.00481% | ||||
| Hail | $291,673,614,404 | $421,121 | 1,602,305 | $2,003,804 | $144 | $51,189 | 0.000687% | ||||
| Heat Wave | $291,673,614,404 | $421,121 | 1,602,305 | $1,316 | $10 | $256,418,109 | under 0.0001% | ||||
| Hurricane | $291,583,235,335 | $421,121 | 1,601,564 | $11,522,453 | $1,537 | $496,730 | 0.00395% | ||||
| Ice Storm | $291,206,091,966 | n/a | 1,599,816 | $411,084 | n/a | $577,669 | 0.000141% | ||||
| Inland Flooding | $291,554,040,317 | $11,659 | 10,788 | $262,808,562 | $565 | $3,248,009 | n/a (see note) | $85,000 | 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 | $2,267,428,590 | n/a | 10,067 | $7,158 | n/a | $9 | 0.000316% | ||||
| Lightning | $291,673,614,404 | n/a | 1,602,305 | $12,252 | n/a | $1,488,047 | under 0.0001% | ||||
| Strong Wind | $291,673,614,404 | $421,121 | 1,602,305 | $640,350 | $1 | $2,860,443 | 0.00022% | $0 | |||
| Tornado | $291,673,614,404 | $421,121 | 1,602,305 | $6,605,994 | $5 | $14,496,551 | 0.00226% | ||||
| Tsunami | n/a | n/a | n/a | n/a | n/a | n/a | NRI publishes no building exposure for this county | ||||
| Wildfire | $1,296,906,165 | $45,409 | 8,352 | $7,330 | under $1 | $1,474 | 0.000565% | ||||
| Winter Weather | $291,673,614,404 | $421,121 | 1,602,305 | $192,166 | under $1 | $1,743,016 | under 0.0001% |
Totals since 2026-06-04 (Storm Events through 2026-06-30): 16 county-coded records, 7 with a damage value recorded (including $0), $85,000; 1 zone-level records, 0 with a damage value recorded (including $0), $0 reported for the zone; Public Assistance: no counted declaration since the plan.
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 | 1,602,305 |
| Building value (total, not at risk) | $291,673,614,404 |
| Agriculture value (total, not at risk) | $421,121 |
| NRI risk rating (all hazards) | Very High |
| Expected annual loss, buildings and agriculture, all hazards | $311,672,980 |
| 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) | $355,399,018 |
| Social vulnerability rating | Very High |
| Community resilience rating | Relatively Moderate |
| 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) | 4 | Severe repetitive loss, FMA definition (44 CFR 77.2) | 35 |
| Repetitive loss, NFIP insurance definition | 141 | Severe repetitive loss, NFIP insurance definition | 34 |
The state NFIP coordinator's list, the source FEMA's Handbook names, often uses the NFIP insurance definition (second row).
Repeat-flood properties: county and state-level rows
Sources: 1, 4
| Scope | RL, FMAproperties | SRL, FMAproperties | RL, NFIPproperties | SRL, NFIPproperties | Any categoryproperties | Mitigatedproperties | Currently insuredproperties |
|---|---|---|---|---|---|---|---|
| County total | 4 | 35 | 141 | 34 | 142 | 0 | 69 |
| of which: Philadelphia city | 4 | 35 | 132 | 34 | 133 | 0 | 69 |
| of which: Unknown (community ID Unknown in FEMA data) | 0 | 0 | 9 | 0 | 9 | 0 | 0 |
| Statewide, no county in FEMA's file | 0 | 0 | 1 | 0 | 1 | 0 | 0 |
The statewide row counts properties FEMA's file gives with no county in this state; they are listed for reference and are not in this county's counts.
Repeat-flood properties by jurisdiction in the plan (NFIP community)
Sources: 1, 4
| Jurisdiction | NFIP community ID | RL, FMAproperties | SRL, FMAproperties | RL, NFIPproperties | SRL, NFIPproperties | Any categoryproperties | Mitigatedproperties | Currently insuredproperties |
|---|---|---|---|---|---|---|---|---|
| Philadelphia city | 420757 | 4 | 35 | 132 | 34 | 133 | 0 | 69 |
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 | RL, FMAproperties | SRL, FMAproperties | RL, NFIPproperties | SRL, NFIPproperties | Any categoryproperties | Mitigatedproperties | Currently insuredproperties |
|---|---|---|---|---|---|---|---|
| single-family residential | 1 | 20 | 96 | 19 | 97 | 0 | 49 |
| 2 to 4 unit residential | 0 | 1 | 9 | 1 | 9 | 0 | 4 |
| other residential | 0 | 2 | 10 | 2 | 10 | 0 | 8 |
| non-residential | 3 | 12 | 26 | 12 | 26 | 0 | 8 |
| not reported | 0 | 0 | 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 1 property is FMA repetitive loss but not NFIP repetitive loss, and 138 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). Philadelphia County, PA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 42101). Automated baseline. https://hazardplain.org/pa/42101/ 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: contact@hazardplain.org