Hazard Plain Automated baseline

Imperial County, CA

Risk-assessment baseline packet

County FIPS:
06025
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: Expired on 2026-01-27. Plan: Imperial County (FEMA plan 107003), approved 2021-01-28.

Since the plan was approved on 2021-01-28: 3 new hazard declarations (2 incidents): EM-3592-CA (Severe Winter Storms, Flooding, Landslides, and Mudslides), DR-4699-CA (Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides), DR-4750-CA (Tropical Storm Hilary).

NOAA Storm Events records since that date: 179 records (data through 2026-06-30).

Highest expected annual loss (FEMA National Risk Index, modeled total; see B1-a): Earthquake ($100,891,671 a year), Inland Flooding ($42,518,994) and Heat Wave ($3,109,221).

Repetitive-loss flood properties now: FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 13.

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:
Expired on 2026-01-27
Plan:
Imperial County (FEMA plan 107003)
Approved:
2021-01-28
Days since expiry:
246
Update underway:
none recorded in FEMA's plan tracker

Until a new plan is approved, FEMA mitigation project grants (HMGP, FMA) need a FEMA exception (44 CFR 201.6(a)(3)).

What changed since your last plan (approved 2021-01-28)

New federal declarations:
3 new hazard declarations (2 incidents): EM-3592-CA (Severe Winter Storms, Flooding, Landslides, and Mudslides), DR-4699-CA (Severe Winter Storms, Straight-Line Winds, Flooding, Landslides, and Mudslides), DR-4750-CA (Tropical Storm Hilary)
Storm Events records since approval:
179 records (data through 2026-06-30)
Repetitive loss now:
FMA RL 0, SRL 0 (44 CFR 77.2); any definition: 13
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
Imperial CountyCountyExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Brawley cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Calexico cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Calipatria cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
El Centro cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Holtville cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Imperial cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Westmorland cityCityExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Imperial Unified School DistrictSchool/School DistrictExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246
Imperial County Irrigation DistrictFlood Control DistrictExpired on 2026-01-27Imperial County (FEMA plan 107003)2021-01-282026-01-27-246

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 2026-06-30countStorm Events coverage note
1EarthquakeRelatively HighRelatively High$73,295,724n/a$27,595,947$100,891,671Storm Events does not record earthquakes.
2Inland FloodingRelatively HighRelatively Moderate$42,219,394$3,949$295,650$42,518,994118
3Heat WaveRelatively ModerateRelatively Moderate$1,394$1,280,602$1,827,225$3,109,22151
4Strong WindRelatively ModerateRelatively Low$179,322$110,160$111,578$401,060127Includes 19 High Wind and 6 Strong Wind records (NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition).
5DroughtRelatively ModerateRelatively Lown/a$320,568n/a$320,5680No recorded events in Storm Events since 1996 (data through 2026-06-30).
6WildfireRelatively LowRelatively Low$164,893$2,099$16,753$183,7453
7TornadoVery LowVery Low$42,850$1,252$9,135$53,2372
8HailVery LowVery Low$33,414$4,865$7,527$45,8068
9LightningVery LowVery Low$1,905n/a$32,797$34,7031
10HurricaneVery LowVery Low$671$4,072$0$4,7430Declared 2 times; no Storm Events record of this type.
11Volcanic ActivityRelatively LowRelatively Low$864n/a$1,508$2,3720No recorded events in Storm Events since 1996 (data through 2026-06-30).
12LandslideVery LowVery Low$427n/a$32$4590Declared 4 times; no Storm Events record of this type.
13Winter WeatherVery LowVery Lowunder $1under $1under $1under $10Declared 4 times; no Storm Events record of this type.
14Cold WaveNo RatingNo Expected Annual Losses$0$0$0$00Declared 2 times; no Storm Events record of this type.
Ice StormNot ApplicableNot Applicable0Declared 1 time; no Storm Events record of this type.

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 volcanic activity 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: avalanche, coastal flooding and 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.

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
Earthquaketract 116 (Very High, 99.8); tract 114 (Very High, 99.8); tract 121.01 (Very High, 99.8)
Hurricanetract 111 (Very Low, 32.4); tract 108 (Very Low, 32.2); tract 119.01 (Very Low, 31.4)
Landslidetract 124 (Relatively Low, 87.8); tract 123.01 (Relatively Low, 87.5); tract 123.02 (Very Low, 51.1)
Tornadotract 106 (Very Low, 13.3); tract 105 (Very Low, 11.9); tract 123.02 (Very Low, 11.8)
Volcanic Activitytract 101.02 (Relatively Low, 97.5); tract 101.01 (Relatively Low, 97.4); tract 102 (Relatively Low, 97.4)
Wildfiretract 110.02 (Relatively Moderate, 92.1); tract 110.01 (Relatively Moderate, 90.8); tract 101.01 (Relatively Moderate, 89.5)

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 116 is Census Tract 116). 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
Cold/Wind Chill, Extreme Cold/Wind Chillwind chill0Wind chill: in event narratives only (local data needed).
Frost/Freeze (outside NRI's Cold Wave definition)crop damage0Temperature: in event narratives only (local data needed).
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)10 records, 1990 to 20150.75 in to 1.75 in (median 1.12 in); 10 with a recorded value1.75 in hail, 2010-08-27; same size also recorded on 1990-08-14, 2008-08-07Event records naming jurisdictions in the plan: Brawley city (2 records), El Centro city (2 records).
Excessive Heat, Heatheat index (in event narratives)51 records, 2018 to 2024 (51 zone-level)1 day to 12 days (median 3 days); 47 with a recorded value12 consecutive days, 2023-07-11 to 2023-07-22, zone-levelCountywide (zone-level records).Heat index: in event narratives only (local data needed).
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)0Ice thickness: in event narratives only (local data needed).
Flash Flood, Flood, Lakeshore Flooddamage and flood days (flood depth: FIRM)118 records, 1999 to 2025Flash Flood, 2023-09-01, $30,000,000 property; $50,000 crops (2023 dollars)Event records naming jurisdictions in the plan: El Centro city (5 records), Imperial city (4 records), Holtville city (2 records), Brawley city (1 record), Calexico city (1 record), Calipatria city (1 record).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)0Physical measure: in event narratives only (local data needed).
Lightningannualized frequency (the measure FEMA's Local Mitigation Planning Handbook names)1 record, 2005No damage or casualties reported in 1 record.Event records naming jurisdictions in the plan: El Centro city (1 record).Storm Events lists lightning with damage or casualties; physical measure in event narratives only (local data needed).
High Wind and Strong Wind (outside NRI's Strong Wind definition)wind speed (kt and mph)25 records, 2018 to 2026 (25 zone-level)35 kt (40 mph) to 63 kt (72 mph) (median 53 kt (61 mph)); 25 with a recorded value63 kt (72 mph) measured gust, High Wind, 2023-02-14; NWS zone CAZ567Strong Wind, 2024-07-24, $100,000 property; $0 crops, reported for the zone (2024 dollars)Countywide (zone-level records).
Thunderstorm Windwind speed (kt and mph)113 records, 1955 to 202543 kt (49 mph) to 87 kt (100 mph) (median 52 kt (60 mph)); 106 with a recorded value87 kt (100 mph) estimated gust, Thunderstorm Wind, 2007-09-15Event records naming jurisdictions in the plan: El Centro city (11 records), Calexico city (10 records), Imperial city (7 records), Brawley city (3 records), Holtville city (3 records), Calipatria city (2 records).
TornadoEnhanced Fujita (Fujita before Feb 2007)7 records, 1965 to 2000F/EF0 to F/EF1 (median F/EF0); 6 with a recorded valueF1 tornado, 1965-07-05, 2 mi path length (whole path, pre-1996), 33 yd wide, $30 property; crops not recorded (1965 dollars)Tornado, 1992-05-05, $2,500,000 property; crops not recorded (1992 dollars)Event records naming jurisdictions in the plan: Calipatria 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)0Physical measure: in event narratives only (local data needed).
Wildfireacres burned (local data)3 records, 2020 to 2022 (3 zone-level)Wildfire, 2022-02-09, $350,000 property; crops not reported (2022 dollars); NWS zone CAZ565Countywide (zone-level records).Acres burned: in event narratives only (local data needed).
Winter Storm, Heavy Snow, Blizzard, Lake-Effect Snow, Winter Weather, Sleetnone in data (snowfall: local data)0Snow depth: in event narratives only (local data needed).

Storm Events records are more complete after 1996; before 1996 only Tornado (from 1950), Hail and Thunderstorm Wind (from 1955) exist. Zone-level records whose zone 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 11 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
2023-11-212023-08-19DR-4750-CAMajor disasterTropical Storm HilaryHurricane (primary); also designated: Inland Flooding, Landslide$1,064,686.09new since last plan; within last 5 years
2023-04-032023-02-21DR-4699-CAMajor disasterSevere Winter Storms, Straight-Line Winds, Flooding, Landslides, and MudslidesIce Storm; Inland Flooding; Landslide; Strong Wind; Winter Weather$3,854,058.53new since last plan; within last 5 years
2023-03-102023-03-09EM-3592-CAEmergencySevere Winter Storms, Flooding, Landslides, and MudslidesInland Flooding (primary); also designated: Landslide, Winter Weatherno Public Assistance recordednew since last plan; within last 5 yearssame incident as DR-4699
2020-03-222020-01-20DR-4482-CAMajor disasterCOVID-19 PandemicNon-natural, not counted$17,933,610.51in the 12 months before plan approval
2020-03-132020-01-20EM-3428-CAEmergencyCOVID-19Non-natural, not countedno Public Assistance recordedin the 12 months before plan approvalsame incident as DR-4482
2010-05-072010-04-04DR-1911-CAMajor disasterEarthquakeEarthquake$25,023,516.23
2010-03-082010-01-17DR-1884-CAMajor disasterSevere Winter Storms, Flooding, and Debris and Mud FlowsInland Flooding; Winter Weather$444,703.15
2007-03-132007-01-11DR-1689-CAMajor disasterSevere FreezeCold WavePA not declared for this county
2005-09-132005-08-29EM-3248-CAEmergencyHurricane Katrina EvacuationHurricane: evacuation support, not a local hazard event; not countedno Public Assistance recorded
1995-03-121995-02-13DR-1046-CAMajor disasterSevere Winter Storms, Flooding Landslides, Mud FlowInland Flooding; Landslide; Winter Weatherno Public Assistance recorded
1993-02-031993-01-05DR-979-CAMajor disasterSevere Winter Storm, Mud & Land Slides, & FloodingInland Flooding (primary); also designated: Landslide, Winter Weatherno Public Assistance recorded
1991-02-111990-12-19DR-894-CAMajor disasterSevere FreezeCold WavePA not declared for this county
1983-07-011983-06-16DR-687-CAMajor disasterFloodingInland Floodingno Public Assistance recorded
1979-10-191979-10-19DR-609-CAMajor disasterEarthquakeEarthquakeno Public Assistance recorded
1976-09-211976-09-21DR-521-CAMajor disasterFlooding, Tropical Storm KathleenInland Flooding (primary); also designated: Hurricaneno Public Assistance recorded

School districts and special districts in this county: $274,273.54 (included in the county total above). Public Assistance matched by applicant name to the school districts and special districts FEMA lists as plan participants in this county. They have no row of their own in the jurisdiction table, so their total is listed here. These dollars are already included in the county PA column of the declarations table (the FEMA record places each applicant in this county), so this line is not added to it.

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
1964-04-011964-04-01DR-169-CAMajor disasterSeismic Sea WaveTsunami
1963-12-211963-12-21DR-161-CAMajor disasterFlood Due to Broken DamOther, not an NRI hazard; not counted
1963-02-251963-02-25DR-145-CAMajor disasterSevere Storms, Heavy Rains & FloodingInland Flooding
1962-10-241962-10-24DR-138-CAMajor disasterSevere Storms & FloodingInland Flooding
1962-03-061962-03-06DR-122-CAMajor disasterFloodsInland Flooding
1961-11-161961-11-16DR-119-CAMajor disasterFire (Los Angeles County)Wildfire
1958-04-041958-04-04DR-82-CAMajor disasterHeavy Rainstorms & FloodInland Flooding
1956-12-291956-12-29DR-65-CAMajor disasterForest FireWildfire
1955-12-231955-12-23DR-47-CAMajor disasterFloodInland Flooding
1954-02-051954-02-05DR-15-CAMajor disasterFlood & ErosionInland 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.

5 Fire Management declarations (1977-08-07 to 1988-09-13) FEMA filed as Statewide with no county; each names one local fire. Listed on the state page.

Public Assistance filed under this county for declarations that do not list it: 1 row, $36,505.19

Sources: 2, 3

FEMA numberDeclaredTitleApplicantPA obligatedfederal share obligated, nominal dollars
DR-4305-CA2017-03-16Severe Winter Storms, Flooding, and MudslidesImperial Irrigation District$36,505.19

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

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
Cold Wave0000201996 to 2026-06-30No Storm Events records of this type; 2 federal declared incidents (see declarations table)
Drought0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Earthquake000020Storm Events does not record earthquakes; the USGS earthquake catalog is the source.
Hail10000001955 to 2026-06-30
Heat Wave51251217001996 to 2026-06-30
Hurricane0000211996 to 2026-06-30No Storm Events records of this type; 2 federal declared incidents (see declarations table)
Ice Storm0000111996 to 2026-06-30No Storm Events records of this type; 1 federal declared incident (see declarations table)
Inland Flooding11876667721996 to 2026-06-30
Landslide0000421996 to 2026-06-30No Storm Events records of this type; 4 federal declared incidents (see declarations table)
Lightning1000001996 to 2026-06-30
Strong Wind13876070111955 to 2026-06-30Includes 19 High Wind and 6 Strong Wind records.
Tornado7000001950 to 2026-06-30
Volcanic Activity0000001996 to 2026-06-30No recorded events, 1996 to 2026-06-30, NOAA NCEI Storm Events
Wildfire3212001996 to 2026-06-30
Winter Weather0000411996 to 2026-06-30No Storm Events records of this type; 4 federal declared incidents (see declarations table)

Notable Storm Events records

Sources: 1, 6, 7

DateEvent typeMagnitude or extentDamagenominal dollarsDeaths, injuriesdirect onlyLocationFlagsWhy listed
2024-07-24Strong Wind48 kt (55 mph) estimated gust$100,000 property; $0 crops, reported for the zone (2024 dollars)0, 0NWS zone CAZ565 (IMPERIAL COUNTY SOUTHEAST), zone-levelnew since last plan; within last 5 yearsB1-c most damaging: High Wind and Strong Wind
2023-09-01Flash Flood$30,000,000 property; $50,000 crops (2023 dollars)0, 0NILAND to IRISnew since last plan; within last 5 yearsB1-c worst recorded: Flash Flood, Flood, Lakeshore Flood
2023-07-11Excessive Heat$0 property; $0 crops, reported for the zone (2023 dollars)0, 0NWS zone CAZ562 (IMPERIAL COUNTY SOUTHWEST), zone-levelnew since last plan; within last 5 yearsB1-c worst recorded: Excessive Heat, Heat
2023-02-14High Wind63 kt (72 mph) measured gust$0 property; $0 crops, reported for the zone (2023 dollars)0, 0NWS zone CAZ567 (IMPERIAL VALLEY), zone-levelnew since last plan; within last 5 yearsB1-c worst recorded: High Wind and Strong Wind
2022-02-09Wildfire$350,000 property; crops not reported, reported for the zone (2022 dollars)0, 0NWS zone CAZ565 (IMPERIAL COUNTY SOUTHEAST), zone-levelnew since last plan; within last 5 yearsB1-c worst recorded: Wildfire
2021-08-31Flash Flood$5,000 property; $0 crops (2021 dollars)2, 0PALO VERDEnew since last plandeaths or injuries recorded
2020-06-28Wildfireproperty not reported; $0 crops, reported for the zone (2020 dollars)1, 0NWS zone CAZ567 (IMPERIAL VALLEY), zone-levelin the 12 months before plan approvaldeaths or injuries recorded
2012-07-30Flood$400,000 property; $0 crops (2012 dollars)0, 5DIXIELANDdeaths or injuries recorded
2010-08-27Hail1.75 inproperty not reported; $0 crops (2010 dollars)0, 0BRAWLEYB1-c worst recorded: Hail
2007-09-15Thunderstorm Wind87 kt (100 mph) estimated gust$4,000,000 property; $0 crops (2007 dollars)0, 0PALO VERDEB1-c worst recorded: Thunderstorm Wind
1992-05-05TornadoF0, 0.2 mi path length (whole path, pre-1996), 10 yd wide$2,500,000 property; crops not recorded (1992 dollars)0, 0location not recordedB1-c most damaging: Tornado
1965-07-05TornadoF1, 2 mi path length (whole path, pre-1996), 33 yd wide$30 property; crops not recorded (1965 dollars)0, 0location not recordedB1-c worst recorded: Tornado

The full list is in the Excel file, sheet "B1-d Storm Events history" (328 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
Cold Wave0event-days per yearnone modeledevent-days in 0 of 30 years, 1996 to 2025 (0%)02005-11-12 to 2024-11-12 (19 years)countywideNo Storm Events cold wave record, 1996 to 2025.
Drought39.3event-days per yearabout 39.3 days per yearevent-days in 0 of 30 years, 1996 to 2025 (0%)1,2182000 to 2025 (25.25 years; D3 and D4 only)countywideNo Storm Events drought record, 1996 to 2025
Earthquake0.151annual probability at a locationchance a given location in the county has at least minor-damage shaking in a year: 15.1%not shownmodeledsee B1-fNo descriptor (Storm Events does not record earthquakes).
Hail0.053events per yearabout 1 in 19 yearsPossibleFEMA annualized frequency (modeled)2.1 (modeled)1986 to 2023 (38 years)countywide
Heat Wave16.9event-days per yearabout 16.9 days per yearLikely (from Storm Events: 7 of 30 years)event-days in 7 of 30 years, 1996 to 2025 (23.3%)1072005-11-12 to 2024-11-12 (19 years)countywide
Hurricane0.0185events per yearabout 1 in 54 yearsPossibleFEMA annualized frequency (modeled)61851 to 2024 (Atlantic); 1949 to 2024 (Pacific)see B1-fNRI counts hurricane and tropical storm tracks passing within storm-force wind range; federal declarations are in B1-d.
Ice Stormevent-days per year1946-12-31 to 2014-02-12 (67 years)countywideNot Applicable in NRI for this county; no descriptor.
Inland Flooding1.54event-days per yearabout 1.54 days per yearLikely (from Storm Events: 20 of 30 years)event-days in 20 of 30 years, 1996 to 2025 (66.7%)431996 to 2023 (28 years)see B1-f
Landslide6.46events per year (modeled)about 6.46 per yearHighly likelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Lightning11.3days per year with a strikeabout 11.3 days per yearHighly likelyFEMA annualized frequency (modeled)not shown1995 to 2023 (29 years; CONUS)countywide
Strong Wind0.278events per yearabout 1 in 4 yearsLikelyFEMA annualized frequency (modeled)111986 to 2023 (38 years)countywide
Tornado0.0961events per yearabout 1 in 10 yearsPossibleFEMA annualized frequency (modeled)not shown1950 to 2023 (EF2+); 1986 to 2023 (EF0-1)see B1-f
Volcanic Activity0.0001annual probabilityabout 1 in 10,000 yearsUnlikelyFEMA annualized frequency (modeled)not shownmodeledsee B1-f
Wildfire0.000783annual probability at a locationchance a given location in the county burns in a year: 0.0783%Possible (from Storm Events: 2 of 30 years)Storm Events records in 2 of 30 years, 1996 to 2025 (6.67%)not shownmodeledsee B1-fDescriptor from Storm Events, not NRI.
Winter Weather0.0000648event-days per yearabout 0.0000648 days per yearevent-days in 0 of 30 years, 1996 to 2025 (0%)0.001152005-11-12 to 2024-11-12 (19 years)countywideNo Storm Events winter weather record, 1996 to 2025

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 20255300.167
Hail2.00 in+1996 to 20250300
Thunderstorm Wind (counted as NRI Strong Wind)50-64 kt1996 to 202591303.03
Thunderstorm Wind (counted as NRI Strong Wind)65 kt+1996 to 20256300.2
Thunderstorm Wind (counted as NRI Strong Wind)unmeasured or below 50 kt1996 to 20255300.167
TornadoEF0-11996 to 20252300.0667
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
Cold Wave0 of 40No Rating 40
Drought31 of 4066.881.694.7Relatively Moderate 5, Relatively Low 13, Very Low 13, No Rating 9
Earthquake40 of 4087.997.499.8Very High 20, Relatively High 18, Relatively Moderate 2
Hail40 of 4015.424.243.5Relatively Low 2, Very Low 38
Heat Wave40 of 4042.474.295.3Relatively High 8, Relatively Moderate 28, Relatively Low 4
Hurricane40 of 4012.415.532.4Very Low 40
Ice Storm0 of 40Not Applicable 40
Inland Flooding40 of 4034.682.799.1Very High 5, Relatively High 17, Relatively Moderate 17, Relatively Low 1
Landslide20 of 4010.322.687.8Relatively Low 2, Very Low 18, No Rating 20
Lightning40 of 400.76.914.8Very Low 40
Strong Wind40 of 4024.740.071.2Relatively Moderate 6, Relatively Low 34
Tornado40 of 401.82.913.3Very Low 40
Volcanic Activity40 of 4043.472.897.5Relatively Low 5, Very Low 35
Wildfire37 of 4031.964.792.1Relatively Moderate 3, Relatively Low 14, Very Low 20, No Rating 3
Winter Weather2 of 4010.510.510.6Very Low 2, No Rating 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 drought, hail, heat wave, 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
Imperial CountyCountyExpired on 2026-01-27FMA RL 0, SRL 0; any 13$6,436,195.280 total; 0 since its planIncludes $2,381,308.63 for declarations not counted as hazard incidents (DR-4482-CA).
Brawley cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0$31,977.666 total; 0 since its plan
Calexico cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0$6,640,958.0511 total; 5 since its planIncludes $1,410,560.93 for declarations not counted as hazard incidents (DR-4482-CA).
Calipatria cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0$119,675.994 total; 1 since its plan
El Centro cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0$1,438,359.8719 total; 7 since its plan
Holtville cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0$2,214,448.645 total; 1 since its plan
Imperial cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0$592,194.8211 total; 5 since its planIncludes $81,044.91 for declarations not counted as hazard incidents (DR-4482-CA).
Westmorland cityCityExpired on 2026-01-27FMA RL 0, SRL 0; any 0no Public Assistance recorded0 total; 0 since its plan

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

School districts and special districts get a plan clock row only.

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 2021-01-28county-coded records, property plus crops, nominal dollarsZone-level damage since planproperty plus crops, reported for the zonePublic Assistance since plannominal dollars; see noteNote
Cold Wave$0$00$0$0$0building exposure is 0 in NRI
Droughtn/a$1,459,697,722n/an/a$320,568n/a0.022% (agriculture)NRI has no building exposure for this hazard; agriculture shown
Earthquake$64,719,748,547n/a179,702$73,295,724n/a$27,595,9470.113%
Hail$37,660,451,760$2,394,483,066179,319$33,414$4,865$7,527under 0.0001%
Heat Wave$37,660,451,760$2,394,483,066179,319$1,394$1,280,602$1,827,225under 0.0001%$0
Hurricane$37,651,422,582$2,386,277,198179,311$671$4,072$0under 0.0001%$1,064,686.09
Ice Storm$3,854,058.53Not Applicable in NRI for this county
Inland Flooding$37,647,239,105$138,124,403737$42,219,394$3,949$295,650n/a (see note)$37,730,500$4,918,744.62NRI 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$22,475,893n/a48$427n/a$320.0019%$4,918,744.62
Lightning$37,660,451,760n/a179,319$1,905n/a$32,797under 0.0001%
Strong Wind$37,660,451,760$2,394,483,066179,319$179,322$110,160$111,5780.000476%$3,422,000$239,000$3,854,058.53Storm Events damage since the plan includes 3 zone-level High Wind records ($127,000) and 4 zone-level Strong Wind records ($112,000): NOAA non-thunderstorm wind types, outside NRI's Strong Wind definition.
Tornado$37,660,451,760$2,394,483,066179,319$42,850$1,252$9,1350.000114%
Volcanic Activity$37,660,451,760n/a179,319$864n/a$1,508under 0.0001%
Wildfire$2,610,341,330$821,339,45516,948$164,893$2,099$16,7530.00632%$357,500
Winter Weather$13,766,831$111,75315under $1under $1under $1under 0.0001%$3,854,058.53

Totals since 2021-01-28 (Storm Events through 2026-06-30): 129 county-coded records, 129 with a damage value recorded (including $0), $41,152,500; 50 zone-level records, 50 with a damage value recorded (including $0), $596,500 reported for the zone; Public Assistance: $4,918,744.62 on 3 counted declarations, 2 of them with Public Assistance.

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
Population179,319
Building value (total, not at risk)$37,660,451,760
Agriculture value (total, not at risk)$2,394,483,066
NRI risk rating (all hazards)Relatively High
Expected annual loss, buildings and agriculture, all hazards$117,668,427
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)$29,898,153
Social vulnerability ratingVery High
Community resilience ratingVery Low
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)0Severe repetitive loss, FMA definition (44 CFR 77.2)0
Repetitive loss, NFIP insurance definition13Severe repetitive loss, NFIP insurance definition0

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 total001301300
of which: Imperial County (unincorporated area)001301300
Statewide, no county in FEMA's file0130410

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 insuredproperties
Imperial County060065001301300
Brawley city0600660000000
Calexico city0600670000000
Calipatria city0600680000000
El Centro city0606700000000
Holtville city0600700000000
Imperial city0600710000000
Westmorland city0600720000000

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 residential0090900
2 to 4 unit residential0000000
other residential0000000
non-residential0040400
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 0 properties are FMA repetitive loss but not NFIP repetitive loss, and 13 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):

  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, organized by the items of FEMA's Local Mitigation Plan Review Tool, Element B. Each section heading names the item its tables support; the plan and FEMA's review decide whether the 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). Imperial County, CA: risk-assessment baseline packet, release 2026-10 (data as of 2026-09-30; County FIPS 06025). Automated baseline. https://hazardplain.org/ca/06025/ 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

Hazard Plain release 2026-10. As of 2026-09-30; Storm Events data through 2026-06-30. Automated baseline.