National Weather ServiceWashingtonDense Fog AdvisoryArchive to October 1, 2026
Dense Fog Advisories in Washington
The National Weather Service issued 52 dense fog advisories for Washington in 2025 and 33 a year on average in 2008-2025; in 2021-2025 it had the 22nd most of any state. 2026 through September: 33, 123% above the average of 15 for those months in 2008-2025. Greater Vancouver Area was covered most often (142 times since 2008).
How many dense fog advisories does Washington get?
Every dense fog advisory that covered part of Washington. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 33 |
| 2025 | 52 |
| 2024 | 66 |
| 2023 | 66 |
| 2022 | 50 |
| 2021 | 20 |
| 2020 | 31 |
| 2019 | 37 |
| 2018 | 29 |
| 2017 | 14 |
| 2016 | 15 |
| 2015 | 41 |
| 2014 | 26 |
| 2013 | 33 |
| 2012 | 11 |
| 2011 | 14 |
| 2010 | 26 |
| 2009 | 31 |
| 2008 | 29 |
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 Washington 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 Washington?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Greater Vancouver Area | 142 | 18 | February 14, 2024 |
| Spokane Area | 125 | 38 | February 6, 2026 |
| Upper Columbia Basin | 107 | 35 | September 14, 2026 |
| Lower Columbia and I - 5 Corridor in Cowlitz County | 92 | 12 | February 13, 2024 |
| Foothills of the Blue Mountains of Washington | 83 | 42 | February 15, 2026 |
| Moses Lake Area | 77 | 28 | September 14, 2026 |
| Yakima Valley | 71 | 34 | February 8, 2026 |
| Kittitas Valley | 68 | 32 | February 16, 2026 |
| Lower Columbia Basin of Washington | 54 | 28 | February 12, 2026 |
| Southwest Interior | 51 | 14 | March 1, 2025 |
| Washington Palouse | 51 | 19 | February 6, 2026 |
| Northeast Mountains | 50 | 19 | February 5, 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 Washington.