Big Horn County, Montana: hazard history

FEMA declared 9 disasters that named Big Horn County between 1978 and 2025.

Most recent declarations

• DR-4902 2025 · Straight-Line Winds · Severe Winter Storm And Straight-line Winds
• FM-5403 2021 · Fire · Pf Fire
• DR-4508 2020 · Biological · Covid-19 Pandemic
• EM-3476 2020 · Biological · Covid-19
• DR-1996 2011 · Severe Storm · Severe Storms And Flooding
• EM-3253 2005 · Hurricane · Hurricane Katrina Evacuation
• DR-1377 2001 · Severe Storm · Severe Winter Storms
• DR-1340 2000 · Fire · Wildfires
• DR-558 1978 · Flood · Severe Storms & Flooding

Not counted above: 29 statewide declarations, which covered every county in Montana. A declaration is a decision to send federal help, not a measure of how bad an event was. Records run from 1953. Source: FEMA OpenFEMA Disaster Declarations Summaries.

Records start in 1996. Damage is NOAA's estimate at the time, in nominal dollars, and is often rounded; it is not insurance claims data. A storm that crossed two NOAA zones in this county is recorded, and counted, once per zone.

NOAA storm event records in Big Horn County each year. The busiest year was 2001, with 45 records.

Years with no record are left out of the table, not shown as zero.

Costliest records

1. Flood · May 21, 2011$4.0M
   NOAA name: BIG HORN · NOAA record 338130
2. Heavy Snow · Apr 9, 2001$1.2M
   NOAA name: BIG HORN · NOAA record 5239388
3. Hail · Jul 5, 1998$100K
   NOAA name: BIG HORN · NOAA record 5658168
4. Thunderstorm Wind · Jul 23, 2000$10K
   NOAA name: BIG HORN · NOAA record 5164199
5. Thunderstorm Wind · Jul 27, 2000$4K
   NOAA name: BIG HORN · NOAA record 5164674

Deadliest records

1. Thunderstorm Wind · Jul 16, 20082 deaths
   NOAA name: BIG HORN · NOAA record 124499
2. Lightning · Jul 17, 19991 death
   NOAA name: BIG HORN · NOAA record 5707970
3. Winter Weather · Feb 19, 20091 death
   NOAA name: SOUTHERN BIG HORN · 1 injury · NOAA record 151028
4. Flash Flood · May 24, 20111 death
   NOAA name: BIG HORN · NOAA record 309029
5. Heat · Aug 17, 20111 death
   NOAA name: NORTHERN BIG HORN · NOAA record 335278

Each line is one NOAA record, linked to its page at NOAA. One large storm can appear more than once if NOAA recorded it in several zones of this county. Dollars are nominal.

The National Flood Insurance Program paid $245K on 16 claims in Big Horn County from 1978 to 2011.

A count of claims, not a rate: NFIP publishes no count of insured homes beside it, and most flood damage is uninsured. Nominal dollars. Records run from 1978 to 2024; claims filed without a county code are not on any county page. Source: FEMA OpenFEMA FIMA NFIP Redacted Claims.

A hazard vulnerability analysis rates each hazard for probability, impact, preparedness and response. Probability is the one column the county’s federal record can fill — NCEI storm events from 1996 to 2026 and FEMA declarations naming the county — and this is what it says for a facility here, on the 0–3 scale of the all-hazards structure surveyors expect. The other six columns are the facility’s own judgment about its building, and Calchis leaves them blank.

A dash means the record does not speak to that hazard; it is not a zero. Whether a finished document satisfies the CMS Emergency Preparedness Rule is the facility’s finding and its surveyor’s. Complete the HVA for a facility in Big Horn County — the technological, human and hazardous-materials rows, the six facility columns, the approval and the printed document — or read the sample analysis on that page first.

• Every figure is counted from public federal records held by Calchis: NOAA NCEI Storm Events, FEMA OpenFEMA Disaster Declarations, and FEMA NFIP claims. Nothing is modeled or estimated.
• NOAA files some events by county and others by forecast zone, and names both. Records are counted as Big Horn County when their NOAA name is this county's name, alone or with a word like “Coastal” or “Inland” in front. The county codes NOAA also publishes have not been loaded for Montana yet; when they are, this page will count by code instead, and some counties' records will grow. NOAA names counted here: BIG HORN, NORTHERN BIG HORN, SOUTHERN BIG HORN, Southern Big Horn. Zones named for something else, such as a mountain range or two counties at once, are left out: 24% of Montana's NOAA records.
• Counts last rebuilt from the source records on Sep 15, 2026.
• This county's NOAA record is short (under 100 records, under 10 with damage, or under 10 years), so this page is not offered to search engines. It is still accurate.