States › Montana › Gallatin County › Flood
Flood in Gallatin County, Montana
15 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 15 flood events in Gallatin County, Montana, between 1950 and 2026, spread over 9 years.
May is the busiest month, with 4 of the recorded events. The last 20 years account for 11 events against 4 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 1.3% of the 1,175 flood events recorded in Montana; its 0.6 per 100 square miles compares with 0.8 statewide.
Compared with Montana
| Measure | Gallatin County | Montana | US |
|---|---|---|---|
| Flood events since 1950 | 15 | 1,175 | 183,559 |
| Per 100 square miles | 0.6 | 0.8 | 5.2 |
| Per 10,000 residents | 1.2 | 10.6 | 5.5 |
| Deaths recorded | 0 | 9 | 2,961 |
| Busiest month | May | June | June |
By year
Seasonality
1Feb
2Mar
3Apr
1May
4Jun
2Jul
1Aug
1Sep
0Oct
0Nov
0Dec
0
Recorded events
All 15 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 |
|---|---|---|---|---|---|---|---|
| 10 Apr 2023 | Flood | — | $1.0M | — | — | — | County |
| 2 Aug 2021 | Flash Flood | — | — | — | — | — | County |
| 26 Feb 2019 | Flood | — | — | — | — | — | County |
| 6 Mar 2014 | Flood | — | — | — | — | — | County |
| 7 Jun 2011 | Flood | — | — | — | — | — | County |
| 2 Jan 2011 | Flood | — | — | — | — | — | County |
| 22 Jul 2008 | Flash Flood | — | — | — | — | — | County |
| 24 May 2008 | Flood | — | — | — | — | — | County |
| 23 May 2008 | Flood | — | — | — | — | — | County |
| 12 Mar 2007 | Flood | — | — | — | — | — | County |
| 5 Feb 2007 | Flood | — | — | — | — | — | County |
| 21 May 2006 | Flood | — | — | — | — | — | County |
| 1 Jun 2003 | Flood | — | — | — | — | — | Forecast zone |
| 30 May 2003 | Flood | — | — | — | — | — | Forecast zone |
| 12 Mar 2003 | Flood | — | $500K | — | — | — | Forecast zone |
Questions and answers
How many flood events has Gallatin County had?
15 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 Gallatin County?
10 Apr 2023 (Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Gallatin County?
The flood of 10 Apr 2023, with property damage estimated by NCEI at $1.0M.
How does Gallatin County compare with Montana for flood?
0.6 events per 100 square miles against 0.8 statewide; the county holds 15 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.