National Weather ServiceMassachusettsDense Fog AdvisoryArchive to October 1, 2026
Dense Fog Advisories in Massachusetts
The National Weather Service issued 4 dense fog advisories for Massachusetts in 2025 and 18 a year on average in 2008-2025; in 2021-2025 it had the 40th most of any state. 2026 through September: 0, 100% below the average of 14 for those months in 2008-2025. Nantucket was covered most often (224 times since 2008).
How many dense fog advisories does Massachusetts get?
Every dense fog advisory that covered part of Massachusetts. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 0 |
| 2025 | 4 |
| 2024 | 12 |
| 2023 | 20 |
| 2022 | 24 |
| 2021 | 13 |
| 2020 | 25 |
| 2019 | 22 |
| 2018 | 40 |
| 2017 | 32 |
| 2016 | 8 |
| 2015 | 29 |
| 2014 | 12 |
| 2013 | 25 |
| 2012 | 15 |
| 2011 | 14 |
| 2010 | 7 |
| 2009 | 11 |
| 2008 | 9 |
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 Massachusetts 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 Massachusetts?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| Nantucket | 224 | 22 | July 1, 2025 |
| Dukes | 220 | 24 | July 1, 2025 |
| Barnstable | 215 | 26 | July 1, 2025 |
| Southern Bristol | 214 | 23 | July 1, 2025 |
| Southern Plymouth | 209 | 22 | July 1, 2025 |
| Eastern Plymouth | 149 | 18 | March 31, 2025 |
| Western Plymouth | 136 | 17 | March 31, 2025 |
| Northern Bristol | 134 | 17 | March 31, 2025 |
| Eastern Norfolk | 104 | 13 | March 31, 2025 |
| Eastern Essex | 98 | 13 | March 31, 2025 |
| Western Norfolk | 97 | 13 | March 31, 2025 |
| Suffolk | 91 | 12 | March 31, 2025 |
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 Massachusetts.