National Weather ServiceMarylandDense Fog AdvisoryArchive to October 1, 2026
Dense Fog Advisories in Maryland
The National Weather Service issued 13 dense fog advisories for Maryland in 2025 and 26 a year on average in 2008-2025; in 2021-2025 it had the 36th most of any state. 2026 through September: 23, 45% above the average of 16 for those months in 2008-2025. Frederick was covered most often (151 times since 2008).
How many dense fog advisories does Maryland get?
Every dense fog advisory that covered part of Maryland. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 23 |
| 2025 | 13 |
| 2024 | 30 |
| 2023 | 20 |
| 2022 | 38 |
| 2021 | 19 |
| 2020 | 48 |
| 2019 | 23 |
| 2018 | 43 |
| 2017 | 17 |
| 2016 | 16 |
| 2015 | 36 |
| 2014 | 22 |
| 2013 | 23 |
| 2012 | 44 |
| 2011 | 21 |
| 2010 | 19 |
| 2009 | 23 |
| 2008 | 18 |
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 |
|---|---|---|---|
| Frederick | 151 | 21 | March 6, 2026 |
| Carroll | 141 | 20 | May 26, 2026 |
| Washington | 139 | 23 | August 15, 2026 |
| Northern Baltimore | 130 | 18 | May 26, 2026 |
| Southern Baltimore | 119 | 14 | March 8, 2026 |
| Anne Arundel | 118 | 16 | May 25, 2026 |
| Central and Eastern Allegany | 112 | 24 | August 21, 2026 |
| Cecil | 104 | 15 | May 26, 2026 |
| Prince Georges | 100 | 11 | May 25, 2026 |
| Northwest Montgomery | 86 | 16 | March 6, 2026 |
| Queen Anne's | 86 | 17 | April 3, 2026 |
| Kent | 85 | 15 | April 3, 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 dense fog advisory?
A dense fog advisory means fog will cut visibility to a quarter mile or less over a wide area. 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.