Mosquito season in Columbia County, GA: when it starts and ends

Mosquito months in Columbia County

In a normal year mosquito season in Columbia County, GA starts around March 13 and ends around November 18, about 36 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 Columbia County, and when

• Start tipping out standing water weekly by February 27.
• Book any yard treatment for mid March, ahead of the July peak.
• Repellent can go away after November 18.
• 5 West Nile cases since 2016 (last 2025): you should use repellent at dusk May to September, more so if over 60.

Columbia County against the rest of GA

Columbia County has the 113th longest season of 159 GA counties, at 250 days against 347 in Glynn County and 199 in Union County. Its mean temperature is 63.7°F.

• Jefferson County: March 12 to November 20 (253 days, 0 WNV)
• Walker County: March 11 to November 16 (250 days, 0 WNV)
• Cobb County: March 14 to November 19 (250 days, 11 WNV)
• Douglas County: March 14 to November 19 (250 days, 2 WNV)

West Nile in Columbia County

From 1999 to 2025, CDC ArboNET counted 11 human West Nile cases in Columbia County (6 neuroinvasive) across 8 years. The worst was 2012 with 4; the latest was 2025.

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