National Weather ServiceCaliforniaHeat AdvisoryArchive to October 1, 2026
Heat Advisories in California
The National Weather Service issued 46 heat advisories for California in 2025 and 30 a year on average in 2008-2025; in 2021-2025 it had the 10th most of any state. 2026 through September: 64, 132% above the average of 28 for those months in 2008-2025. East Bay Interior Valleys was covered most often (86 times since 2008).
How many heat advisories does California get?
Every heat advisory that covered part of California. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 64 |
| 2025 | 46 |
| 2024 | 67 |
| 2023 | 44 |
| 2022 | 59 |
| 2021 | 55 |
| 2020 | 55 |
| 2019 | 53 |
| 2018 | 38 |
| 2017 | 48 |
| 2016 | 12 |
| 2015 | 21 |
| 2014 | 9 |
| 2013 | 6 |
| 2012 | 0 |
| 2011 | 3 |
| 2010 | 1 |
| 2009 | 6 |
| 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 California 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 California?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| East Bay Interior Valleys | 86 | 29 | September 8, 2026 |
| Santa Clara Valley (including San Jose) | 84 | 29 | September 8, 2026 |
| North Bay Interior Valleys | 76 | 17 | September 8, 2026 |
| San Bernardino and Riverside County Valleys-The Inland Empire | 76 | 32 | September 11, 2026 |
| Santa Clarita Valley | 73 | 27 | September 8, 2026 |
| Southern Salinas Valley/Arroyo Seco and Lake San Antonio | 70 | 22 | September 8, 2026 |
| San Diego County Inland Valleys | 67 | 24 | September 11, 2026 |
| Santa Lucia Mountains and Los Padres National Forest | 65 | 20 | September 8, 2026 |
| Los Angeles County San Gabriel Valley | 64 | 30 | September 8, 2026 |
| Santa Cruz Mountains | 63 | 17 | September 8, 2026 |
| Orange County Inland | 59 | 22 | September 11, 2026 |
| Northern Salinas Valley/Hollister Valley and Carmel Valley | 57 | 11 | September 8, 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 California.