National Weather ServiceMarylandHeat AdvisoryArchive to October 1, 2026
Heat Advisories in Maryland
The National Weather Service issued 21 heat advisories for Maryland in 2025 and 14 a year on average in 2008-2025; in 2021-2025 it had the 32nd most of any state. 2026 through September: 22, 60% above the average of 14 for those months in 2008-2025. Southern Baltimore was covered most often (105 times since 2008).
How many heat advisories does Maryland get?
Every heat advisory that covered part of Maryland. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 22 |
| 2025 | 21 |
| 2024 | 32 |
| 2023 | 7 |
| 2022 | 16 |
| 2021 | 11 |
| 2020 | 16 |
| 2019 | 10 |
| 2018 | 16 |
| 2017 | 12 |
| 2016 | 21 |
| 2015 | 8 |
| 2014 | 1 |
| 2013 | 6 |
| 2012 | 26 |
| 2011 | 20 |
| 2010 | 16 |
| 2009 | 3 |
| 2008 | 5 |
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 Maryland 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 Maryland?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Southern Baltimore | 105 | 29 | July 18, 2026 |
| Calvert | 101 | 28 | September 3, 2026 |
| Charles | 100 | 30 | September 3, 2026 |
| St. Marys | 100 | 28 | September 3, 2026 |
| Anne Arundel | 97 | 29 | July 18, 2026 |
| Prince Georges | 95 | 30 | July 18, 2026 |
| Cecil | 80 | 27 | July 16, 2026 |
| Northern Baltimore | 71 | 24 | July 16, 2026 |
| Caroline | 70 | 18 | September 3, 2026 |
| Talbot | 70 | 18 | September 3, 2026 |
| Queen Anne's | 69 | 17 | September 3, 2026 |
| Frederick | 68 | 26 | July 16, 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 Maryland.