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Flood in Fallon County, Montana
16 floods and flash floods events in the NCEI Storm Events record, 1950 to 2026. Event types counted: Flood, Flash Flood, Coastal Flood, Lakeshore Flood.
NCEI notes that Storm Data is compiled from a variety of sources including the National Weather Service, other federal, state and local agencies, the media and the public; that property and crop damage figures are estimates; and that some events are recorded by NWS forecast zone rather than by county. FEMA notes that NFIP claim records are redacted and aggregated to protect the privacy of policyholders. Storm records through 30 Jun 2026.
NCEI records 16 flood events in Fallon County, Montana, between 1950 and 2026, spread over 10 years.
June is the busiest month, with 10 of the recorded events. The last 20 years account for 11 events against 5 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 1.4% of the 1,175 flood events recorded in Montana; its 1.0 per 100 square miles compares with 0.8 statewide.
Compared with Montana
| Measure | Fallon County | Montana | US |
|---|---|---|---|
| Flood events since 1950 | 16 | 1,175 | 183,559 |
| Per 100 square miles | 1.0 | 0.8 | 5.2 |
| Per 10,000 residents | 53.0 | 10.6 | 5.5 |
| Deaths recorded | 0 | 9 | 2,961 |
| Busiest month | June | June | June |
By year
Seasonality
0Feb
0Mar
0Apr
0May
2Jun
10Jul
3Aug
1Sep
0Oct
0Nov
0Dec
0
Recorded events
All 16 events, most recent first. Magnitude is hail size, tornado rating or wind speed as recorded.
| Date | Event type | Magnitude | Property damage | Crop damage | Deaths | Injuries | Geography |
|---|---|---|---|---|---|---|---|
| 3 Jul 2022 | Flash Flood | — | — | — | — | — | County |
| 17 Jun 2014 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 18 May 2013 | Flash Flood | — | — | — | — | — | County |
| 20 May 2011 | Flood | — | $375K | — | — | — | County |
| 16 Jun 2010 | Flash Flood | — | — | — | — | — | County |
| 15 Jun 2009 | Flash Flood | — | — | — | — | — | County |
| 15 Jun 2009 | Flash Flood | — | — | — | — | — | County |
| 15 Jun 2009 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2005 | Flood | — | — | — | — | — | Forecast zone |
| 10 Jul 2004 | Flash Flood | — | — | — | — | — | County |
| 26 Jul 2001 | Flash Flood | — | — | — | — | — | County |
| 20 Aug 1998 | Flash Flood | — | — | — | — | — | County |
| 23 Jun 1998 | Flash Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has Fallon County had?
16 events in the NCEI Storm Events record between 1950 and 2026. Reporting of floods and flash floods became far more complete after 1996, so early decades undercount.
When was the last recorded flood event in Fallon County?
3 Jul 2022 (Flash Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Fallon County?
The flood of 20 May 2011, with property damage estimated by NCEI at $375K.
How does Fallon County compare with Montana for flood?
1.0 events per 100 square miles against 0.8 statewide; the county holds 16 of the state's 1,175 recorded events.
Provenance
NOAA NCEI Storm Events Database, yearly details files through 30 Jun 2026, public domain. County-recorded events plus zone-recorded events whose forecast zone is named for the county (marked "Forecast zone"). Population and area from the US Census Bureau (2021). Built 1 Oct 2026. See the methodology, the Flood hub and the county page.