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Flood in Yellowstone County, Montana
38 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.
Yellowstone County, Montana, has 38 flood events in the NCEI record since 1950, with at least one in 15 different years.
June is the busiest month, with 14 of the recorded events. The last 20 years account for 24 events against 14 in the 20 years before, a change that reflects reporting practice as much as weather.
The county holds 3.2% of the 1,175 flood events recorded in Montana; its 1.4 per 100 square miles compares with 0.8 statewide.
NCEI attributes 1 death in the county to floods and flash floods.
Compared with Montana
| Measure | Yellowstone County | Montana | US |
|---|---|---|---|
| Flood events since 1950 | 38 | 1,175 | 183,559 |
| Per 100 square miles | 1.4 | 0.8 | 5.2 |
| Per 10,000 residents | 2.3 | 10.6 | 5.5 |
| Deaths recorded | 1 | 9 | 2,961 |
| Busiest month | June | June | June |
By year
Seasonality
2Feb
1Mar
2Apr
0May
6Jun
14Jul
11Aug
0Sep
1Oct
1Nov
0Dec
0
Recorded events
All 38 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 |
|---|---|---|---|---|---|---|---|
| 28 Jul 2025 | Flood | — | — | — | — | — | County |
| 2 Jun 2023 | Flash Flood | — | $1.6M | — | — | — | County |
| 24 Jul 2022 | Flash Flood | — | — | — | — | — | County |
| 24 Jul 2022 | Flash Flood | — | — | — | — | — | County |
| 24 Jul 2022 | Flash Flood | — | — | — | — | — | County |
| 27 May 2019 | Flood | — | — | — | — | — | County |
| 27 Jul 2018 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2018 | Flash Flood | — | — | — | — | — | County |
| 19 Jun 2015 | Flash Flood | — | — | — | — | — | County |
| 10 Jun 2015 | Flash Flood | — | — | — | — | — | County |
| 1 Jun 2015 | Flash Flood | — | — | — | — | — | County |
| 27 May 2014 | Flood | — | — | — | — | — | County |
| 9 Mar 2014 | Flood | — | — | — | — | — | County |
| 6 Mar 2014 | Flood | — | — | — | — | — | County |
| 7 Sep 2013 | Flash Flood | — | — | — | — | — | County |
| 22 Jun 2013 | Flash Flood | — | — | — | — | — | County |
| 26 May 2013 | Flash Flood | — | — | — | — | — | County |
| 24 May 2011 | Flash Flood | — | — | — | — | — | County |
| 21 May 2011 | Flood | — | $300K | — | 1 | — | County |
| 10 May 2011 | Flood | — | — | — | — | — | County |
| 20 Jun 2010 | Flash Flood | — | $2.7M | — | — | — | County |
| 16 Jun 2010 | Flood | — | — | — | — | — | County |
| 7 Jul 2007 | Flash Flood | — | — | — | — | — | County |
| 7 Jul 2007 | Flash Flood | — | — | — | — | — | County |
| 4 Jul 2004 | Flood | — | — | — | — | — | Forecast zone |
| 17 Jul 2001 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2001 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2001 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2001 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2001 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2001 | Flash Flood | — | — | — | — | — | County |
| 26 Jun 2001 | Flash Flood | — | — | — | — | — | County |
| 2 Oct 1998 | Flood | — | — | — | — | — | County |
| 31 Jul 1998 | Flood | — | — | — | — | — | County |
| 30 Jul 1998 | Flood | — | — | — | — | — | County |
| 2 Feb 1997 | Flood | — | — | — | — | — | County |
| 3 Jan 1997 | Flash Flood | — | — | — | — | — | County |
| 2 Jan 1997 | Flood | — | — | — | — | — | County |
Questions and answers
How many flood events has Yellowstone County had?
38 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 Yellowstone County?
28 Jul 2025 (Flood). Records reach NCEI about 120 days after the month ends.
What was the most damaging flood event recorded in Yellowstone County?
The flash flood of 20 Jun 2010, with property damage estimated by NCEI at $2.7M.
How does Yellowstone County compare with Montana for flood?
1.4 events per 100 square miles against 0.8 statewide; the county holds 38 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.