National Weather ServiceArizonaDense Fog AdvisoryArchive to October 1, 2026
Dense Fog Advisories in Arizona
The National Weather Service issued 6 dense fog advisories for Arizona in 2025 and 8 a year on average in 2008-2025; in 2021-2025 it had the 47th most of any state. 2026 through September: 6, 50% above the average of 4 for those months in 2008-2025. Upper San Pedro River Valley including Sierra Vista/Benson was covered most often (30 times since 2008).
How many dense fog advisories does Arizona get?
Every dense fog advisory that covered part of Arizona. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 6 |
| 2025 | 6 |
| 2024 | 14 |
| 2023 | 7 |
| 2022 | 7 |
| 2021 | 9 |
| 2020 | 10 |
| 2019 | 19 |
| 2018 | 11 |
| 2017 | 1 |
| 2016 | 4 |
| 2015 | 12 |
| 2014 | 5 |
| 2013 | 5 |
| 2012 | 0 |
| 2011 | 13 |
| 2010 | 7 |
| 2009 | 5 |
| 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 Arizona 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 Arizona?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Upper San Pedro River Valley including Sierra Vista/Benson | 30 | 8 | January 2, 2026 |
| Northwest Pinal County | 27 | 9 | January 2, 2026 |
| Upper Santa Cruz River and Altar Valleys including Nogales | 27 | 5 | January 2, 2026 |
| Eastern Cochise County Below 5000 Feet including Douglas/Willcox | 23 | 6 | January 2, 2026 |
| Tucson Metro Area including Tucson/Green Valley/Marana/Vail | 22 | 2 | January 2, 2026 |
| Yuma | 19 | 6 | January 8, 2026 |
| South Central Pinal County including Eloy/Picacho Peak State Park | 17 | 3 | January 2, 2026 |
| Southeast Pinal County including Kearny/Mammoth/Oracle | 17 | 2 | January 2, 2026 |
| Upper Gila River and Aravaipa Valleys including Clifton/Safford | 17 | 5 | January 2, 2026 |
| South Mountain/Ahwatukee | 16 | 5 | January 2, 2026 |
| Southeast Valley/Queen Creek | 16 | 5 | January 2, 2026 |
| West Pinal County | 16 | 5 | March 16, 2024 |
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 Arizona.