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

Mosquito months in Orleans Parish

In a normal year mosquito season in Orleans Parish, LA starts around January 18 and ends around January 11, about 51 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Orleans Parish, and when

• Start tipping out standing water weekly by January 4.
• Book any yard treatment for mid January, ahead of the August peak.
• Repellent can go away after January 11.
• 8 West Nile cases since 2016 (last 2025): you should use repellent at dusk April to October, more so if over 60.

Orleans Parish against the rest of LA

Orleans Parish has the 1st longest season of 64 LA counties, at 358 days against 358 in Orleans Parish and 247 in Claiborne Parish. Its mean temperature is 70.5°F.

• Plaquemines Parish: January 17 to January 9 (357 days, 0 WNV)
• St. Charles Parish: January 20 to January 7 (352 days, 2 WNV)

West Nile in Orleans Parish

From 1999 to 2025, CDC ArboNET counted 92 human West Nile cases in Orleans Parish (52 neuroinvasive) across 15 years. The worst was 2002 with 22; the latest was 2025.

Background: where mosquitoes never stop; how the dates are worked out.