National Weather ServiceExtreme Heat WatchVTEC EH.A, XH.AArchive to October 1, 2026
Extreme Heat Watch: what it means and how often it is issued
The National Weather Service issued 117 extreme heat watches in 2025 and 74 a year on average in 2008-2025; California, Arizona and Mississippi got the most in 2021-2025. 2026 through September: 135, 84% above the average of 73 for those months in 2008-2025.
What is an extreme heat watch?
An extreme heat watch means dangerous heat is possible in the coming days. It replaced the excessive heat watch in 2025. 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. AreaZine's counts include the excessive heat watches issued before the change.
Source: National Weather Service directives and glossary.
How many extreme heat watches a year?
National count: each extreme heat watch counted once, whatever the number of states it covers. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 137 |
| 2025 | 117 |
| 2024 | 141 |
| 2023 | 188 |
| 2022 | 84 |
| 2021 | 114 |
| 2020 | 87 |
| 2019 | 78 |
| 2018 | 68 |
| 2017 | 53 |
| 2016 | 50 |
| 2015 | 16 |
| 2014 | 14 |
| 2013 | 21 |
| 2012 | 68 |
| 2011 | 107 |
| 2010 | 70 |
| 2009 | 19 |
| 2008 | 31 |
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?
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.
Which states get the most extreme heat watches?
Yearly average per state, 2021-2025. A extreme heat watch covering two states counts in both.
| State | A year, 2021-2025 | A year, 2008-2025 | 2025 |
|---|---|---|---|
| California | 35 | 22 | 18 |
| Arizona | 17 | 14 | 19 |
| Mississippi | 9 | 4 | 3 |
| Oregon | 9 | 4 | 11 |
| Florida | 8 | 3 | 6 |
| Washington | 8 | 4 | 9 |
| Nevada | 7 | 5 | 5 |
| Louisiana | 7 | 2 | 1 |
| Texas | 6 | 3 | 0 |
| Georgia | 6 | 2 | 7 |
| Puerto Rico | 6 | 2 | 0 |
| Idaho | 5 | 2 | 2 |
| Iowa | 5 | 3 | 10 |
| Nebraska | 5 | 3 | 10 |
| Minnesota | 4 | 3 | 10 |
| Alabama | 4 | 2 | 0 |
| Missouri | 4 | 4 | 9 |
| Ohio | 4 | 2 | 6 |
| Illinois | 4 | 3 | 8 |
| Pennsylvania | 3 | 4 | 6 |
| Indiana | 3 | 2 | 3 |
| Utah | 3 | 2 | 1 |
| Kansas | 3 | 3 | 3 |
| North Carolina | 3 | 2 | 9 |
| Wisconsin | 3 | 2 | 8 |
| West Virginia | 3 | 2 | 6 |
| Montana | 3 | 1 | 0 |
| New Jersey | 3 | 3 | 4 |
| Virginia | 3 | 2 | 6 |
| Kentucky | 3 | 2 | 3 |
| Maryland | 2 | 2 | 4 |
| Arkansas | 2 | 2 | 2 |
| Michigan | 2 | 1 | 3 |
| Delaware | 2 | 2 | 2 |
| Tennessee | 2 | 2 | 2 |
| Connecticut | 2 | 1 | 3 |
| District of Columbia | 2 | 1 | 3 |
| New York | 2 | 1 | 4 |
| South Carolina | 2 | 1 | 4 |
| New Mexico | 2 | 1 | 1 |
| Oklahoma | 1 | 1 | 0 |
| South Dakota | 1 | 1 | 3 |
| Massachusetts | 1 | 1 | 1 |
| Rhode Island | 1 | 0 | 1 |
| Maine | 1 | 0 | 2 |
| North Dakota | 0 | 0 | 1 |
| New Hampshire | 0 | 0 | 1 |
| Colorado | 0 | 0 | 0 |
| Vermont | 0 | 0 | 2 |
| Wyoming | 0 | 0 | 0 |
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 extreme heat watches in AreaZine's record
NWS San DiegoWatchSeptember 30, 2026
Extreme Heat Watch: San Diego County Coastal Areas, San Bernardino and Riverside County Valleys-The Inland Empire, San Diego County Inland Valleys and 3 more, CA
In force until 9:00 p.m. PDT, October 7, 2026
NWS Los Angeles/OxnardWatchSeptember 30, 2026
Extreme Heat Watch: Catalina and Santa Barbara Islands, Santa Clarita Valley, Ventura County Beaches and 16 more, CA
In force until 8:00 p.m. PDT, October 8, 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).
Extreme Heat Watch or extreme heat warning?
A extreme heat watch (for a wide area, hours or days ahead) means the conditions are possible: be ready; a extreme heat warning (from the local NWS office, for the area at risk) means the hazard is happening or imminent: act now. An extreme heat warning means dangerous heat is expected, measured by heat index or temperature thresholds each office sets. It replaced the excessive heat warning in 2025. A warning means the hazard is happening, about to happen, or very likely: act now to protect people and property. The NWS issued 183 extreme heat warnings in 2025, against 117 extreme heat watches. The extreme heat warning record.