Mosquito season in Simpson County, MS: when it starts and ends

Mosquito months in Simpson County

In a normal year mosquito season in Simpson County, MS starts around February 23 and ends around January 4, about 45 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 Simpson County, and when

• Start tipping out standing water weekly by February 9.
• Book any yard treatment for late February, ahead of the July peak.
• Repellent can go away after January 4.
• 1 West Nile case since 2016 (last 2024): you should use repellent at dusk May to September, more so if over 60.

Simpson County against the rest of MS

Simpson County has the 2nd longest season of 82 MS counties, at 315 days against 333 in Harrison County and 221 in Tishomingo County. Its mean temperature is 67.3°F.

• Harrison County: February 1 to December 31 (333 days, 7 WNV)
• Stone County: February 27 to January 8 (315 days, 1 WNV)
• Pearl River County: February 24 to January 3 (313 days, 3 WNV)

West Nile in Simpson County

From 1999 to 2025, CDC ArboNET counted 11 human West Nile cases in Simpson County (4 neuroinvasive) across 7 years. The worst was 2002 with 4; the latest was 2024.

Background: when the season starts across the US; how the dates are worked out.