National Weather ServiceIdahoHeat AdvisoryArchive to October 1, 2026
Heat Advisories in Idaho
The National Weather Service issued 21 heat advisories for Idaho in 2025 and 7 a year on average in 2008-2025; in 2021-2025 it had the 29th most of any state. 2026 through September: 20, 169% above the average of 7 for those months in 2008-2025. Lewiston Area was covered most often (42 times since 2008).
How many heat advisories does Idaho get?
Every heat advisory that covered part of Idaho. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 20 |
| 2025 | 21 |
| 2024 | 18 |
| 2023 | 10 |
| 2022 | 23 |
| 2021 | 23 |
| 2020 | 10 |
| 2019 | 2 |
| 2018 | 9 |
| 2017 | 4 |
| 2016 | 0 |
| 2015 | 7 |
| 2014 | 4 |
| 2013 | 3 |
| 2012 | 0 |
| 2011 | 0 |
| 2010 | 0 |
| 2009 | 0 |
| 2008 | 0 |
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 |
|---|---|---|---|
| Lewiston Area | 42 | 18 | August 25, 2026 |
| Eastern Magic Valley | 30 | 12 | August 21, 2026 |
| Lower Hells Canyon/Salmon River Region | 29 | 12 | August 21, 2026 |
| Lower Snake River Plain | 29 | 12 | August 21, 2026 |
| Shoshone/Lava Beds | 29 | 13 | August 21, 2026 |
| Lewis and Southern Nez Perce Counties | 28 | 12 | August 21, 2026 |
| Lower Treasure Valley | 28 | 17 | August 20, 2026 |
| Upper Treasure Valley | 28 | 15 | August 20, 2026 |
| Coeur d'Alene Area | 27 | 13 | August 21, 2026 |
| Orofino/Grangeville Region | 26 | 10 | August 21, 2026 |
| Arco/Mud Lake Desert | 25 | 11 | August 21, 2026 |
| Idaho Palouse | 25 | 11 | August 21, 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.
What is a heat advisory?
A heat advisory means heat that can make people ill, especially those without cooling, below the office's extreme heat warning values. An advisory is issued for a hazard less serious than a warning that can still cause inconvenience or danger if people are not careful. The national record · Every warning type in Idaho.