National Weather ServiceLouisianaDense Fog AdvisoryArchive to October 1, 2026
Dense Fog Advisories in Louisiana
The National Weather Service issued 113 dense fog advisories for Louisiana in 2025 and 71 a year on average in 2008-2025; in 2021-2025 it had the 9th most of any state. 2026 through September: 53, 38% above the average of 38 for those months in 2008-2025. St. John The Baptist was covered most often (394 times since 2008).
How many dense fog advisories does Louisiana get?
Every dense fog advisory that covered part of Louisiana. 2026 is an outline: the year is not over.
The numbers
| Year | Count |
|---|---|
| 2026 (through September) | 53 |
| 2025 | 113 |
| 2024 | 92 |
| 2023 | 72 |
| 2022 | 60 |
| 2021 | 94 |
| 2020 | 63 |
| 2019 | 84 |
| 2018 | 50 |
| 2017 | 85 |
| 2016 | 60 |
| 2015 | 57 |
| 2014 | 69 |
| 2013 | 65 |
| 2012 | 77 |
| 2011 | 73 |
| 2010 | 50 |
| 2009 | 56 |
| 2008 | 50 |
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 Louisiana 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 Louisiana?
| County or forecast zone | Since 2008 | Since 2023 | Last issued |
|---|---|---|---|
| St. John The Baptist | 394 | 100 | April 11, 2026 |
| St. Charles | 384 | 94 | March 27, 2026 |
| Lower St. Martin | 376 | 84 | March 27, 2026 |
| East Cameron | 371 | 107 | March 27, 2026 |
| Upper Jefferson | 371 | 86 | March 27, 2026 |
| West Cameron | 371 | 107 | March 27, 2026 |
| Upper Plaquemines | 369 | 88 | April 11, 2026 |
| Upper St. Bernard | 366 | 86 | March 27, 2026 |
| Upper Lafourche | 365 | 93 | March 27, 2026 |
| Lafayette | 363 | 81 | March 27, 2026 |
| Lower Jefferson | 363 | 87 | March 27, 2026 |
| St. James | 362 | 100 | April 11, 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 Louisiana.