National Weather ServiceIdahoFlash Flood WatchArchive to October 1, 2026
Flash Flood Watches in Idaho
The National Weather Service issued 14 flash flood watches for Idaho in 2025 and 9 a year on average in 2008-2025; in 2021-2025 it had the 19th most of any state. 2026 through September: 13, 49% above the average of 9 for those months in 2008-2025. Boise Mountains was covered most often (50 times since 2008).
How many flash flood watches does Idaho get?
Every flash flood watch that covered part of Idaho. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 13 |
| 2025 | 14 |
| 2024 | 1 |
| 2023 | 1 |
| 2022 | 1 |
| 2021 | 11 |
| 2020 | 1 |
| 2019 | 7 |
| 2018 | 5 |
| 2017 | 2 |
| 2016 | 9 |
| 2015 | 7 |
| 2014 | 16 |
| 2013 | 17 |
| 2012 | 7 |
| 2011 | 8 |
| 2010 | 18 |
| 2009 | 31 |
| 2008 | 9 |
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 Idaho 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 Idaho?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Boise Mountains | 50 | 11 | September 18, 2026 |
| West Central Mountains | 43 | 10 | September 18, 2026 |
| Big and Little Wood River Region | 31 | 0 | August 22, 2014 |
| Sawtooth Mountains | 27 | 0 | July 10, 2016 |
| Southwest Highlands | 24 | 2 | August 26, 2025 |
| Owyhee Mountains | 23 | 2 | August 26, 2025 |
| South Central Highlands | 23 | 0 | September 22, 2016 |
| Caribou Highlands | 22 | 0 | September 22, 2016 |
| Southern Twin Falls County | 21 | 1 | August 26, 2025 |
| Lemhi | 20 | 0 | August 2, 2021 |
| Camas Prairie | 18 | 2 | September 18, 2026 |
| Wasatch Mountains/Idaho Portion | 18 | 0 | September 22, 2016 |
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.
What is a flash flood watch?
A flash flood watch means the rain or conditions that lead to flash flooding are possible in the coming hours. Since 2022 most NWS offices issue a flood watch in its place: the national count fell from 692 in 2021 to 76 in 2022, while flood watches rose from 203 to 715 (IEM archive), so compare the two together. A watch means the conditions for the hazard are possible or favourable, but it is not yet happening: be ready to act if a warning follows. The national record · Every warning type in Idaho.