Mosquito season in Ascension Parish, LA: when it starts and ends

Mosquito months in Ascension Parish

In a normal year mosquito season in Ascension Parish, LA starts around February 1 and ends around December 28, about 47 weeks.

What to do in Ascension Parish, and when

Start tipping out standing water weekly by January 18.
Book any yard treatment for early February, ahead of the July peak.
Repellent can go away after December 28.
19 West Nile cases since 2016: you should wear EPA-registered repellent at dusk May to September, and check LA spray notices.

Ascension Parish against the rest of LA

Ascension Parish has the 19th longest season of 64 LA counties, at 330 days against 358 in Orleans Parish and 247 in Claiborne Parish. Its mean temperature is 68.2°F.

Jefferson Davis Parish: January 31 to December 28 (331 days, 3 WNV)
Vermilion Parish: January 29 to December 25 (330 days, 1 WNV)
Assumption Parish: February 1 to December 28 (330 days, 3 WNV)
St. Martin Parish: January 29 to December 24 (329 days, 2 WNV)

West Nile in Ascension Parish

From 1999 to 2025, CDC ArboNET counted 90 human West Nile cases in Ascension Parish (46 neuroinvasive) across 15 years. The worst was 2006 with 22; the latest was 2025.

See how the dates are worked out, and where mosquitoes never stop.