National Weather ServiceColoradoDense Fog AdvisoryArchive to October 1, 2026
Dense Fog Advisories in Colorado
The National Weather Service issued 43 dense fog advisories for Colorado in 2025 and 34 a year on average in 2008-2025; in 2021-2025 it had the 31st most of any state. 2026 through September: 9, 61% below the average of 23 for those months in 2008-2025. Kit Carson County was covered most often (176 times since 2008).
How many dense fog advisories does Colorado get?
Every dense fog advisory that covered part of Colorado. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 9 |
| 2025 | 43 |
| 2024 | 41 |
| 2023 | 37 |
| 2022 | 21 |
| 2021 | 30 |
| 2020 | 37 |
| 2019 | 58 |
| 2018 | 36 |
| 2017 | 51 |
| 2016 | 38 |
| 2015 | 54 |
| 2014 | 30 |
| 2013 | 26 |
| 2012 | 20 |
| 2011 | 24 |
| 2010 | 28 |
| 2009 | 21 |
| 2008 | 11 |
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 Colorado 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 Colorado?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Kit Carson County | 176 | 40 | August 6, 2026 |
| Yuma County | 169 | 37 | September 17, 2026 |
| Cheyenne County | 151 | 34 | August 6, 2026 |
| Grand Valley | 90 | 14 | January 24, 2026 |
| Central and South Weld County | 65 | 22 | December 4, 2025 |
| Central Yampa River Basin | 53 | 9 | January 6, 2026 |
| Larimer County Below 6000 Feet/Northwest Weld County | 50 | 15 | December 4, 2025 |
| Logan County | 49 | 11 | October 15, 2025 |
| Morgan County | 47 | 12 | December 4, 2025 |
| Northeast Weld County | 47 | 13 | October 27, 2025 |
| Phillips County | 47 | 12 | October 9, 2025 |
| North Douglas County Below 6000 Feet/Denver/West Adams and Arapahoe Counties/East Broomfield County | 46 | 12 | April 27, 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 Colorado.