Hazard Plain Automated baseline

Polk County, OR

Risk-assessment baseline packet

County FIPS:
41053
Release:
2026-10
Data as of:
2026-09-30
Storm Events data through:
2026-06-30

Hazard Plain is an independent product built from public federal data. It is not a FEMA document and is not reviewed or endorsed by FEMA or any state agency.

Hazard Plain release 2026-10, as of 2026-09-30.

Summary

Plan status as of 2026-09-30: Approved, expires 2029-09-18. Plan: Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028), approved 2024-09-19.

Since the plan was approved on 2024-09-19: 1 new hazard declaration (1 incident) and 8 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): Earthquake ($19,369,994 a year), Inland Flooding ($14,679,590) and Heat Wave ($2,967,256).

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 2029-09-18
Plan:
Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028)
Approved:
2024-09-19
Days to expiry:
1,084

What changed since your last plan (approved 2024-09-19)

New federal declarations:
1 new hazard declaration (1 incident): DR-4907-OR (Severe Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides)
Storm Events records since approval:
8 records (data through 2026-06-30)
Repetitive loss now:
FMA RL 1, SRL 1 (44 CFR 77.2); any definition: 2
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

JurisdictionTypeStatusPlanApprovedExpiresDays to expirynegative = days since expiry
Polk CountyCountyApproved, expires 2029-09-18Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028)2024-09-192029-09-181,084
Dallas cityCityApproved, expires 2029-09-18Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028)2024-09-192029-09-181,084
Falls City cityCityApproved, expires 2029-09-18Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028)2024-09-192029-09-181,084
Independence cityCityApproved, expires 2029-09-18Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028)2024-09-192029-09-181,084
Monmouth cityCityApproved, expires 2029-09-18Polk County Multi-Jurisdictional Natural Hazard Mitigation Plan (FEMA plan 109028)2024-09-192029-09-181,084
Salem cityCityApproved, expires 2028-12-04City of Salem Natural Hazards Mitigation Plan (FEMA plan 109257)2023-12-052028-12-04796

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 EALHazardNRI risk ratingEAL ratingEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL total (see note)modeled dollars per yearStorm Events records, 1996 to 2026-06-30countWhy this hazard can be left outNRI Not Applicable, no declaration and no Storm Events record since 1996Storm Events coverage note
1EarthquakeRelatively ModerateRelatively Moderate$12,416,251n/a$6,953,743$19,369,994Storm Events does not record earthquakes.
2Inland FloodingRelatively LowRelatively Low$14,639,245$13,660$26,684$14,679,59038
3Heat WaveRelatively ModerateRelatively Moderate$466$33,898$2,932,892$2,967,25617
4Ice StormRelatively ModerateRelatively Moderate$114,159n/a$82,220$196,37914
5Cold WaveVery LowRelatively Low$410$5,466$180,817$186,6933Includes 2 Frost/Freeze records (outside NRI's Cold Wave definition; counted in this table and in B1-d, not in the B1-e descriptor).
6LightningRelatively LowRelatively Low$4,166n/a$149,238$153,4040No recorded events in Storm Events since 1996 (data through 2026-06-30).
7TornadoVery LowVery Low$70,958$240$53,248$124,4463
8Strong WindVery LowVery Low$78,807$21$25,804$104,632128Includes 109 High Wind and 16 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
9Winter WeatherRelatively LowRelatively Low$2,798$1,851$38,893$43,54265Includes 1 Sleet record (outside NRI's Winter Weather definition).
10WildfireVery LowVery Low$36,657$5$1,712$38,3743
11LandslideRelatively LowRelatively Low$741n/a$30,542$31,2836
12HailVery LowVery Low$19,452$2,157$3,700$25,3100No recorded events in Storm Events since 1996 (data through 2026-06-30).
13Volcanic ActivityVery LowRelatively Low$7n/a$2,092$2,0990No recorded events in Storm Events since 1996 (data through 2026-06-30).
14AvalancheVery LowVery Low$0n/a$22$220No recorded events in Storm Events since 1996 (data through 2026-06-30).
15DroughtVery LowVery Lown/a$2n/a$20No recorded events in Storm Events since 1996 (data through 2026-06-30).
16Coastal FloodingNo RatingNo Expected Annual Losses$0n/a$0$00No recorded events in Storm Events since 1996 (data through 2026-06-30).
HurricaneNot ApplicableNot Applicable0NRI rates hurricane Not Applicable for this county, and no counted federal declaration for this county names it (EM-3228-OR names it but is not counted as a local occurrence; see B1-d).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 lightning and volcanic activity 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: tsunami. 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

HazardHighest-rated census tractsNRI risk rating, score 0 to 100
Avalanchetract 204 (Very Low, 7.3)
Earthquaketract 202.02 (Very High, 97.8); tract 204 (Relatively High, 96.1); tract 205 (Relatively High, 95.3)
Hurricaneno tract has a National Risk Index rating for this hazard
Landslidetract 204 (Relatively Moderate, 99.0); tract 205 (Relatively Low, 92.1); tract 202.04 (Relatively Low, 88.5)
Tornadotract 202.02 (Relatively Low, 29.6); tract 205 (Very Low, 28.3); tract 53.01 (Very Low, 25.3)
Volcanic Activitytract 202.02 (Relatively Low, 97.0); tract 205 (Relatively Low, 96.9); tract 203.04 (Relatively Low, 96.2)
Wildfiretract 204 (Relatively Low, 86.5); tract 202.04 (Relatively Low, 83.9); tract 205 (Relatively Low, 81.8)

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 204 is Census Tract 204). 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

HazardScaleRecordscount and yearsObserved rangeWorst recorded eventMost damaging (when different)How it applies to jurisdictionsNote
Avalanchenone (count and damage only)0
Coastal Flood, Storm Surge/Tidenone in data (flood depth: FIRM)0Flood depth: see the FEMA Flood Insurance Rate Map.
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill1 record, 1998 (1 zone-level)7 days; 1 with a recorded value7 consecutive days, 1998-12-18 to 1998-12-24, zone-levelCountywide (zone-level records).
Frost/Freeze (outside NRI's Cold Wave definition)crop damage2 records, 2024 (2 zone-level)No crop damage reported in 2 records.Countywide (zone-level records).
DroughtU.S. Drought Monitor scale (D0 to D4)0Storm 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.
EarthquakeModified Mercalli (local data)0Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hailhail size (inches)0
Excessive Heat, Heatheat index (in event narratives)17 records, 2006 to 2022 (17 zone-level)1 day to 5 days (median 3 days); 16 with a recorded value5 consecutive days, 2015-07-01 to 2015-07-05, zone-levelCountywide (zone-level records).
Hurricane, Tropical Storm, Tropical DepressionSaffir-Simpson0Storm 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 StormSperry-Piltz ice scale (local data)14 records, 1996 to 2025 (14 zone-level)Ice Storm, 2021-02-11, $10,000,000 property; $0 crops (2021 dollars); NWS zone ORZ007Countywide (zone-level records).
Flash Flood, Flood, Lakeshore Flooddamage and flood days (flood depth: FIRM)38 records, 1996 to 2025 (11 zone-level)Flood, 1996-02-06, $400,000,000 property; crops not reported (1996 dollars), 7 direct deaths (reported for the zone); NWS zone ORZ004Event records naming jurisdictions in the plan: Falls City city (4 records). Zone-level records (11) 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 Flownone (count and damage only)6 records, 1996 to 2012 (6 zone-level)Debris Flow, 2004-12-08, $50,000 property; crops not reported (2004 dollars); NWS zone ORZ004Countywide (zone-level records).
Lightningannualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)0Storm Events lists lightning with damage or casualties.
High Wind and Strong Wind (outside NRI's Strong Wind definition)wind speed (kt and mph)125 records, 1996 to 2025 (125 zone-level)25 kt (29 mph) to 90 kt (104 mph) (median 58 kt (67 mph)); 124 with a recorded value90 kt (104 mph) measured gust, High Wind, 2017-02-08; NWS zone ORZ004Strong Wind, 2016-10-13, $5,000,000 property; $0 crops (zone total, 2016 dollars)Countywide (zone-level records).
Thunderstorm Windwind speed (kt and mph)3 records, 1996 to 202157 kt (66 mph) to 74 kt (85 mph) (median 70 kt (81 mph)); 3 with a recorded value74 kt (85 mph), measurement type not recorded, Thunderstorm Wind, 1996-01-15Event records naming jurisdictions in the plan: Dallas city (1 record).
TornadoEnhanced Fujita (Fujita before Feb 2007)3 records, 1997 to 2003F/EF0 to F/EF1 (median F/EF0); 3 with a recorded valueF1 tornado, 2003-06-21, 0.3 mi within this county, 30 yd wide, damage not reportedTornado, 1997-09-15, $5,000 property; crops not reported (1997 dollars)Event records naming jurisdictions in the plan: Independence 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).
Volcanic Ash, Volcanic AshfallVolcanic Explosivity Index (local data)0
Wildfireacres burned (local data)3 records, 2020 to 2023 (3 zone-level)No damage reported in 3 records.Countywide (zone-level records).
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)65 records, 1996 to 2024 (65 zone-level)Winter Storm, 2008-12-20, $2,200,000 property; $8,100,000 crops (2008 dollars); NWS zone ORZ007Countywide (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 avalanche, debris flow, lightning and volcanic ash, volcanic ashfall.

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: 15 declarations covering 12 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

DeclaredIncident beganFEMA numberTypeTitleMapped hazardCounty Public Assistancefederal share obligated, nominal dollarsFlagsNotes
2026-04-072025-12-15DR-4907-ORMajor disasterSevere Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesInland Flooding; Landslide; Strong Wind; Winter Weather$8,403.30new since last plan; within last 5 years
2021-05-042021-02-11DR-4599-ORMajor disasterSevere Winter StormWinter Weather$2,072,775.16
2020-03-282020-01-20DR-4499-ORMajor disasterCOVID-19 PandemicNon-natural, not counted$38,804.29
2020-03-132020-01-20EM-3429-OREmergencyCOVID-19Non-natural, not countedno Public Assistance recordedsame incident as DR-4499
2016-02-172015-12-06DR-4258-ORMajor disasterSevere Winter Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesInland Flooding; Landslide; Strong Wind; Winter Weather$1,255,954.17
2012-03-022012-01-17DR-4055-ORMajor disasterSevere Winter Storm, Flooding, Landslides, and MudslidesInland Flooding (primary); also designated: Landslide, Winter Weather$801,380.57
2009-03-022008-12-13DR-1824-ORMajor disasterSevere Winter Storm, Record and Near Record SnowWinter Weather$244,888.84
2007-12-082007-12-01DR-1733-ORMajor disasterSevere Storms, Flooding, Landslides, and MudslidesInland Flooding; Landslide$537,525.29
2007-02-222006-12-14DR-1683-ORMajor disasterSevere Winter Storm and FloodingInland Flooding; Winter Weather$100,938.97
2006-03-202005-12-18DR-1632-ORMajor disasterSevere Storms, Flooding, Landslides, and MudslidesInland Flooding; Landslide$935,466.99
2005-09-072005-08-29EM-3228-OREmergencyHurricane Katrina EvacuationHurricane: evacuation support, not a local hazard event; not countedno Public Assistance recorded
2004-02-192003-12-26DR-1510-ORMajor disasterSevere Winter StormsWinter Weather$172,916.85
1996-02-091996-02-04DR-1099-ORMajor disasterHigh Winds, Severe Storms and FloodingInland Flooding (primary); also designated: Strong Windno Public Assistance recorded
1974-01-251974-01-25DR-413-ORMajor disasterSevere Storms, Snowmelt & FloodingInland Floodingno Public Assistance recorded
1964-12-241964-12-24DR-184-ORMajor disasterHeavy Rains & FloodingInland Floodingno 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

DeclaredIncident beganFEMA numberTypeTitleMapped hazard
1963-02-251963-02-25DR-144-ORMajor disasterFloodsInland Flooding
1962-10-161962-10-16DR-136-ORMajor disasterSevere StormsHazard not mapped (severe storm title names no single hazard); not counted
1957-03-011957-03-01DR-69-ORMajor disasterFloodInland Flooding
1956-07-201956-07-20DR-60-ORMajor disasterStorm & FloodInland Flooding
1955-12-291955-12-29DR-49-ORMajor disasterFloodInland 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.

27 Fire Management declarations (1973-08-17 to 2001-08-17) FEMA filed as Statewide with no county; each names one local fire. Listed on the state page.

Public Assistance not placed in any Oregon county: 1 row, $479,867.27; listed on the Oregon state page.

Source: 3

Previous occurrences by hazard, with explicit no-event rows

Sources: 2, 6, 7

HazardStorm Events records, all years on file(years in the Period column)Since plan approvalrecordsIn the 12 months before plan approvalrecordsLast 5 yearsrecordsDeclared incidents, all yearsseparate disastersDeclared since approvalseparate disastersPeriodStatement
Avalanche0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Coastal Flooding0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Cold Wave3022001996 to 2026-06-30Includes 2 Frost/Freeze records.
Drought0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Earthquake000000Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail0000001955 to 2026-06-30No recorded events, 1955 to 2026-06-30, NOAA NCEI Storm Events
Heat Wave17003001996 to 2026-06-30
Hurricane0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Ice Storm14124001996 to 2026-06-30
Inland Flooding38227911996 to 2026-06-30
Landslide6000511996 to 2026-06-30
Lightning0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Strong Wind1285115311955 to 2026-06-30Includes 109 High Wind and 16 Strong Wind records.
Tornado3000001950 to 2026-06-30
Volcanic Activity0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Wildfire3002001996 to 2026-06-30
Winter Weather65018711996 to 2026-06-30Includes 1 Sleet record.

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationFlagsWhy listed
2022-07-28Excessive Heat$0 property; $0 crops (zone total, 2022 dollars)4, 0NWS zone ORZ007 (CENTRAL WILLAMETTE VALLEY), zone-levelwithin last 5 yearsdeaths or injuries recorded
2021-06-26Excessive Heat$0 property; $0 crops (zone total, 2021 dollars)16, 0NWS zone ORZ007 (CENTRAL WILLAMETTE VALLEY), zone-leveldeaths or injuries recorded
2021-02-11Ice Storm$10,000,000 property; $0 crops (zone total, 2021 dollars)0, 0NWS zone ORZ007 (CENTRAL WILLAMETTE VALLEY), zone-levelB1-c worst recorded: Ice Storm
2017-02-08High Wind90 kt (104 mph) measured gust$0 property; $0 crops (zone total, 2017 dollars)0, 0NWS zone ORZ004 (CENTRAL COAST RANGE OF W OREGON), zone-levelB1-c worst recorded: High Wind and Strong Wind
2015-07-01Heat$0 property; $0 crops (zone total, 2015 dollars)0, 0NWS zone ORZ007 (Central Willamette Valley), zone-levelB1-c worst recorded: Excessive Heat, Heat
2008-12-20Winter Storm$2,200,000 property; $8,100,000 crops (zone total, 2008 dollars)0, 0NWS zone ORZ007 (CENTRAL WILLAMETTE VALLEY), zone-levelB1-c worst recorded: Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleet
2004-12-08Debris Flow$50,000 property; crops not reported (zone total, 2004 dollars)0, 0NWS zone ORZ004 (CENTRAL COAST RANGE OF W OREGON), zone-levelB1-c worst recorded: Debris Flow
2003-06-21TornadoF1, 0.3 mi within this county, 30 yd widedamage not reported0, 0INDEPENDENCEB1-c worst recorded: Tornado
1998-12-18Cold/Wind Chilldamage not reported0, 0Storm Events area CENTRAL WILLAMETTE VALLEY INCLUDING SALEM (legacy zone code ORZ005), zone-levelB1-c worst recorded: Cold/Wind Chill, Extreme Cold/Wind Chill
1997-09-15TornadoF0, 0.5 mi within this county, 10 yd wide$5,000 property; crops not reported (1997 dollars)0, 0MC COYB1-c most damaging: Tornado
1996-02-06Flood$400,000,000 property; crops not reported (zone total, 1996 dollars)7, 0NWS zone ORZ004 (CENTRAL COAST RANGE OF W OREGON), zone-leveldeaths or injuries recorded
1996-01-15Thunderstorm Wind74 kt (85 mph), measurement type not recordeddamage not reported0, 0DALLASB1-c worst recorded: Thunderstorm Wind

The full list is in the Excel file, sheet "B1-d Storm Events history" (277 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).

Tribal and special-area declarations in this state are listed on the state page.

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

Probability: FEMA annualized frequency and descriptor per hazard

Sources: 5, 6

HazardFEMA annualized frequency (modeled)unit per rowUnitIn plain termsDescriptorDescriptor basisNRI events or days in its record period (hail, wind and tornado are area-weighted, so can be fractional)NRI periodLocationNote
Avalanche0.01events per yearabout 1 in 100 yearsPossibleFEMA annualized frequency (modeled)01994 to 2023 (30 years)see B1-f0.01 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.
Coastal Flooding0events per year at a location (modeled)none modeledStorm Events records in 0 of 30 years, 1996 to 2025 (0%)not shownmodeledsee B1-fNo descriptor: no Storm Events record 1996 to 2025
Cold Wave0.0526event-days per yearabout 0.0526 days per yearPossibleStorm Events event-days in 1 of 30 years, 1996 to 2025 (3.33%)12005-11-12 to 2024-11-12 (19 years)countywide
Drought0.315event-days per yearabout 0.315 days per yearStorm Events event-days in 0 of 30 years, 1996 to 2025 (0%)142000 to 2025 (25.25 years; D3 and D4 only)countywideNo Storm Events drought record, 1996 to 2025
Earthquake0.0194annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 1.94%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail0.0413events per yearabout 1 in 24 yearsPossibleFEMA annualized frequency (modeled)1.6 (modeled)1986 to 2023 (38 years)countywide
Heat Wave6.12event-days per yearabout 6.12 days per yearLikelyStorm Events event-days in 9 of 30 years, 1996 to 2025 (30%)96.12005-11-12 to 2024-11-12 (19 years)countywide
Hurricaneevents per year1851 to 2024 (Atlantic); 1949 to 2024 (Pacific)see B1-fNot Applicable in NRI for this county; no descriptor.
Ice Storm0.599event-days per yearabout 0.599 days per yearLikelyStorm Events event-days in 8 of 30 years, 1996 to 2025 (26.7%)411946-12-31 to 2014-02-12 (67 years)countywide
Inland Flooding0.821event-days per yearabout 0.821 days per yearLikelyStorm Events event-days in 21 of 30 years, 1996 to 2025 (70%)231996 to 2023 (28 years)see B1-f
Landslide4.22events per year (modeled)about 4.22 per yearHighly likelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning4.96days per year with a strikeabout 4.96 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind0.0471events per yearabout 1 in 21 yearsPossibleFEMA annualized frequency (modeled)21986 to 2023 (38 years)countywide
Tornado0.0597events per yearabout 1 in 17 yearsPossibleFEMA annualized frequency (modeled)not shown1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)see B1-f
Volcanic Activity0.0101annual probabilityabout 1 in 99 yearsPossibleFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Wildfire0.0000873annual probability at a locationchance a given location in the county burns in a year: 0.00873%LikelyStorm Events records in 3 of 30 years, 1996 to 2025 (10%)not shownmodeledsee B1-f
Winter Weather7.86event-days per yearabout 7.86 days per yearLikelyStorm Events event-days in 23 of 30 years, 1996 to 2025 (76.7%)1492005-11-12 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

UnitDescriptorDefinition
events per yearHighly likely1 or more per year
events per yearLikelyabout once in 1 to 10 years
events per yearPossibleabout once in 10 to 100 years
events per yearUnlikelyless than once in 100 years
annual probabilityLikely10% to under 100% chance in a given year
annual probabilityPossible1% to under 10% chance in a given year
annual probabilityUnlikelyunder 1% chance in a given year
event-days (share of years)Highly likelyevent-days recorded in 90% or more of years
event-days (share of years)Likelyevent-days recorded in 10% to under 90% of years
event-days (share of years)Possibleevent-days recorded in some years but under 10% of years
lightning strike-daysHighly likelycloud-to-ground strikes on 1 or more days per year

Intensity bands: historical frequency (Storm Events)

Source: 6

HazardBandYearsEventscounty-coded recordsYears in periodEvents per yearevents / years
Hail1.00-1.99 in1996 to 20250300
Hail2.00 in+1996 to 20250300
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 20251300.0333
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 20252300.0667
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 20250300
TornadoEF0-11996 to 20253300.1
TornadoEF2-31996 to 20250300
TornadoEF4-51996 to 20250300
Tornadounrated (EFU)1996 to 20250300

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

HazardTractsrated of allNRI risk score, 0 to 100Tracts by rating
MinMedianMax
Avalanche1 of 167.37.37.3Very Low 1, Not Applicable 15
Coastal Flooding0 of 16No Rating 16
Cold Wave16 of 1620.524.332.0Relatively Low 16
Drought1 of 1668.068.068.0Very Low 1, No Rating 15
Earthquake16 of 1684.190.197.8Very High 1, Relatively High 10, Relatively Moderate 5
Hail16 of 1615.324.234.1Very Low 16
Heat Wave16 of 1669.888.795.4Relatively High 10, Relatively Moderate 6
Hurricane0 of 16Not Applicable 16
Ice Storm16 of 1645.870.886.7Relatively Moderate 9, Relatively Low 7
Inland Flooding16 of 169.656.898.4Very High 1, Relatively High 3, Relatively Moderate 6, Relatively Low 5, Very Low 1
Landslide16 of 1618.264.199.0Relatively Moderate 1, Relatively Low 5, Very Low 10
Lightning16 of 1620.041.463.9Relatively Moderate 6, Relatively Low 9, Very Low 1
Strong Wind16 of 1614.125.543.8Relatively Low 11, Very Low 5
Tornado16 of 166.415.329.6Relatively Low 1, Very Low 15
Volcanic Activity16 of 1687.393.097.0Relatively Low 16
Wildfire16 of 1631.261.186.5Relatively Low 6, Very Low 10
Winter Weather16 of 1633.247.165.3Relatively Moderate 8, Relatively Low 8

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

JurisdictionTypePlan statusRepetitive lossFMA RL and SRL (44 CFR 77.2); repeat-flood, any definitionPublic Assistance to this jurisdictionFEMA records matched by applicant name; federal share obligated, nominal dollarsEvent records naming this placeall years; since its planNotes
Polk CountyCountyApproved, expires 2029-09-18FMA RL 1, SRL 1; any 2$3,788,133.650 total; 0 since its plan
Dallas cityCityApproved, expires 2029-09-18FMA RL 0, SRL 0; any 0$418,930.121 total; 0 since its plan
Falls City cityCityApproved, expires 2029-09-18FMA RL 0, SRL 0; any 0$576,499.034 total; 0 since its plan
Independence cityCityApproved, expires 2029-09-18FMA RL 0, SRL 0; any 0$277,778.601 total; 0 since its plan
Monmouth cityCityApproved, expires 2029-09-18FMA RL 0, SRL 0; any 0$313,078.030 total; 0 since its planIncludes $27,822.13 for declarations not counted as hazard incidents (DR-4499-OR).
Salem cityCityApproved, expires 2028-12-04FMA RL 0, SRL 2; any 7no Public Assistance recorded0 total; 0 since its planWhole community, including the part in Lincoln County and Marion County; none of its repeat-flood properties are in this county.

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

HazardBuilding exposuremodeled dollarsAgriculture exposuremodeled dollarsPopulation exposedpeopleEAL buildingsmodeled dollars per yearEAL agriculturemodeled dollars per yearCost of expected deaths and injuriesFEMA's dollar value per year, not property damageEAL as % of exposurebuildings; agriculture where notedStorm Events damage since 2024-09-19county-coded records, property plus crops, nominal dollarsZone-level damage since planproperty plus crops, reported for the zonePublic Assistance since plannominal dollars; see noteNote
Avalanche$0n/aunder 1$0n/a$22building exposure is 0 in NRI
Coastal Flooding$0n/a0$0n/a$0building exposure is 0 in NRI
Cold Wave$17,959,080,306$173,498,77287,390$410$5,466$180,817under 0.0001%
Droughtn/a$4,417,831n/an/a$2n/aunder 0.0001% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$30,062,776,080n/a87,433$12,416,251n/a$6,953,7430.0413%
Hail$17,959,080,306$173,498,77287,390$19,452$2,157$3,7000.000108%
Heat Wave$17,959,080,306$173,498,77287,390$466$33,898$2,932,892under 0.0001%
HurricaneNot Applicable in NRI for this county
Ice Storm$17,957,101,608n/a87,379$114,159n/a$82,2200.000636%$0
Inland Flooding$17,950,187,110$33,875,4363,627$14,639,245$13,660$26,684n/a (see note)$0$8,403.30NRI 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$712,847,714n/a3,340$741n/a$30,5420.000104%$8,403.30
Lightning$17,959,080,306n/a87,390$4,166n/a$149,238under 0.0001%
Strong Wind$17,959,080,306$173,498,77287,390$78,807$21$25,8040.000439%$0$8,403.30
Tornado$17,959,080,306$173,498,77287,390$70,958$240$53,2480.000395%
Volcanic Activity$17,959,080,306n/a87,390$7n/a$2,092under 0.0001%
Wildfire$2,379,130,844$24,791,92711,371$36,657$5$1,7120.00154%
Winter Weather$17,959,080,306$173,498,77287,390$2,798$1,851$38,893under 0.0001%$8,403.30

Totals since 2024-09-19 (Storm Events through 2026-06-30): 2 county-coded records, 2 with a damage value recorded (including $0), $0; 6 zone-level records, 6 with a damage value recorded (including $0), $0 reported for the zone; Public Assistance: $8,403.30 on 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

MeasureValue
Population87,390
Building value (total, not at risk)$17,959,080,306
Agriculture value (total, not at risk)$173,498,772
NRI risk rating (all hazards)Relatively Low
Expected annual loss, buildings and agriculture, all hazards$27,441,417
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)$10,481,608
Social vulnerability ratingVery Low
Community resilience ratingRelatively High
NRI versionDecember 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

DefinitionPropertiesSevere repetitive lossProperties
Repetitive loss, FMA definition (44 CFR 77.2)1Severe repetitive loss, FMA definition (44 CFR 77.2)1
Repetitive loss, NFIP insurance definition1Severe repetitive loss, NFIP insurance definition1

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

ScopeRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
County total1111202
of which: Polk County (unincorporated area)1111202
Statewide, no county in FEMA's file0010100

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

JurisdictionNFIP community IDRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredpropertiesNote
Polk County4101861111202
Dallas city4101870000000
Falls City city4101880000000
Independence city4101890000000
Monmouth city4101900000000
Salem city4101670272702Whole community, including the part in Lincoln County and Marion County; none of its repeat-flood properties are in this county.

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 groupRL, FMApropertiesSRL, FMApropertiesRL, NFIPpropertiesSRL, NFIPpropertiesAny categorypropertiesMitigatedpropertiesCurrently insuredproperties
single-family residential1111202
2 to 4 unit residential0000000
other residential0000000
non-residential0000000
not reported0000000

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 1 property is 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):

  1. FEMA, OpenFEMA HazardMitigationPlanStatuses v1, version 2026-09-29T134039Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/HazardMitigationPlanStatuses (API)
  2. FEMA, OpenFEMA DisasterDeclarationsSummaries v2, version 2026-09-29T162832Z, pulled 2026-09-30, https://www.fema.gov/api/open/v2/DisasterDeclarationsSummaries (API)
  3. FEMA, OpenFEMA PublicAssistanceFundedProjectsSummaries v1, version 2026-09-29T150754Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/PublicAssistanceFundedProjectsSummaries (API)
  4. FEMA, OpenFEMA NfipMultipleLossProperties v1, version 2026-08-04T164045Z, pulled 2026-09-30, https://www.fema.gov/api/open/v1/NfipMultipleLossProperties (API)
  5. 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)
  6. 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/
  7. 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
  8. 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). Polk County, OR: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 41053). Automated baseline. https://hazardplain.org/or/41053/ 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]