National Weather ServiceMontanaFlash Flood WarningArchive to October 1, 2026
Flash Flood Warnings in Montana
The National Weather Service issued 25 flash flood warnings for Montana in 2025 and 21 a year on average in 2008-2025; in 2021-2025 it had the 39th most of any state. 2026 through September: 42, 101% above the average of 21 for those months in 2008-2025. Valley was covered most often (36 times since 2008).
How many flash flood warnings does Montana get?
Every flash flood warning that covered part of Montana. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 42 |
| 2025 | 25 |
| 2024 | 3 |
| 2023 | 67 |
| 2022 | 11 |
| 2021 | 6 |
| 2020 | 1 |
| 2019 | 21 |
| 2018 | 23 |
| 2017 | 2 |
| 2016 | 5 |
| 2015 | 14 |
| 2014 | 10 |
| 2013 | 70 |
| 2012 | 8 |
| 2011 | 56 |
| 2010 | 24 |
| 2009 | 17 |
| 2008 | 14 |
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
When in the year does Montana get them?
Sum of 2008-2025; the busiest month is labelled.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
Where in Montana?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Valley | 36 | 7 | July 30, 2026 |
| Musselshell | 31 | 8 | July 17, 2026 |
| Rosebud | 30 | 13 | July 3, 2026 |
| Yellowstone | 30 | 9 | June 27, 2026 |
| Big Horn | 28 | 7 | June 27, 2026 |
| Powder River | 23 | 1 | June 16, 2025 |
| Stillwater | 23 | 15 | July 15, 2026 |
| Carter | 22 | 1 | June 16, 2025 |
| Carbon | 20 | 10 | June 16, 2025 |
| Lewis and Clark | 20 | 9 | July 23, 2026 |
| Custer | 19 | 5 | June 16, 2025 |
| Dawson | 19 | 2 | June 28, 2026 |
The NWS issues these products for counties or forecast zones; a zone can be part of a county or a mountain range.
Source: Iowa Environmental Mesonet archive of National Weather Service watches, warnings and advisories (VTEC); National Weather Service. Data as of October 1, 2026.
The latest flash flood warnings for Montana in AreaZine's record
NWS BillingsWarningSeptember 18, 2026
Flash Flood Warning: Golden Valley and Sweet Grass, MT
Expired 10:15 p.m. MDT, September 18, 2026
NWS BillingsWarningSeptember 18, 2026
Flash Flood Warning: Golden Valley and Wheatland, MT
Expired 9:00 p.m. MDT, September 18, 2026
NWS Great FallsWarningSeptember 6, 2026
Flash Flood Warning: Hill and Liberty, MT
Expired 1:00 a.m. MDT, September 7, 2026
NWS Great FallsWarningSeptember 6, 2026
Flash Flood Warning: Hill and Liberty, MT
Expired 12:45 a.m. MDT, September 7, 2026
NWS MissoulaWarningAugust 14, 2026
Flash Flood Warning: Ravalli, MT
Expired 11:30 a.m. MDT, August 14, 2026
NWS GlasgowWarningJuly 30, 2026
Flash Flood Warning: Garfield and Valley, MT
Expired 9:00 a.m. MDT, July 30, 2026
NWS Great FallsWarningJuly 22, 2026
Flash Flood Warning: Broadwater and Lewis and Clark, MT
Expired 10:45 p.m. MDT, July 22, 2026
NWS Great FallsWarningJuly 17, 2026
Flash Flood Warning: Broadwater and Lewis and Clark, MT
Expired 1:00 a.m. MDT, July 18, 2026
This list is AreaZine's record of the NWS alert feed, kept since April 6, 2026; the counts above come from the complete IEM archive.
Source: National Weather Service alerts (api.weather.gov).
What is a flash flood warning?
A flash flood warning means flash flooding is happening or about to happen: water rising fast in streams, streets or dry washes, usually within six hours of heavy rain or a dam or levee failure. A warning means the hazard is happening, about to happen, or very likely: act now to protect people and property. The national record · Every warning type in Montana.