Mosquito season in Kings County, CA: when it starts and ends

Mosquito months in Kings County

In a normal year mosquito season in Kings County, CA starts around February 5 and ends around November 30, about 43 weeks.

What to do in Kings County, and when

Start tipping out standing water weekly by January 22.
Book any yard treatment for early February, ahead of the July peak.
Repellent can go away after November 30.
57 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to September, and check CA spray notices.

Kings County against the rest of CA

Kings County has the 24th longest season of 58 CA counties, at 298 days against 365 in Los Angeles County and 110 in Mono County. Its mean temperature is 63.9°F.

Yolo County: February 6 to December 2 (300 days, 93 WNV)
Colusa County: February 5 to December 1 (299 days, 7 WNV)
Tehama County: February 7 to November 30 (297 days, 15 WNV)
Merced County: February 12 to November 27 (288 days, 60 WNV)

West Nile in Kings County

From 1999 to 2025, CDC ArboNET counted 112 human West Nile cases in Kings County (48 neuroinvasive) across 19 years. The worst was 2005 with 32; the latest was 2025.

More: how the dates are worked out · reading the West Nile counts.