Mosquito season in Shelby County, AL: when it starts and ends

Mosquito months in Shelby County

In a normal year mosquito season in Shelby County, AL starts around February 27 and ends around December 1, about 40 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 Shelby County, and when

• Start tipping out standing water weekly by February 13.
• Book any yard treatment for late February, ahead of the July peak.
• Repellent can go away after December 1.
• 9 West Nile cases since 2016 (last 2024): you should use repellent at dusk May to September, more so if over 60.

Shelby County against the rest of AL

Shelby County has the 13th longest season of 67 AL counties, at 277 days against 330 in Montgomery County and 218 in Marion County. Its mean temperature is 64.2°F.

• Barbour County: February 28 to December 3 (278 days, 0 WNV)
• Conecuh County: February 28 to December 3 (278 days, 0 WNV)
• Choctaw County: February 28 to November 29 (274 days, 0 WNV)
• Lowndes County: February 27 to November 25 (271 days, 2 WNV)

West Nile in Shelby County

From 1999 to 2025, CDC ArboNET counted 12 human West Nile cases in Shelby County (12 neuroinvasive) across 6 years. The worst was 2017 with 4; the latest was 2024.

See how the dates are worked out, and reading the West Nile counts.