Mosquito season in Yuba County, CA: when it starts and ends
Mosquito months in Yuba County
In a normal year mosquito season in Yuba County, CA starts around February 27 and ends around November 28, about 39 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Yuba 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 November 28.
- 24 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to September, and check CA spray notices.
Yuba County against the rest of CA
Yuba County has the 31st longest season of 58 CA counties, at 274 days against 365 in Los Angeles County and 110 in Mono County. Its mean temperature is 61.4°F.
- Tulare County: February 23 to November 28 (278 days, 125 WNV)
- Napa County: February 24 to November 27 (276 days, 1 WNV)
- Santa Barbara County: February 27 to November 27 (273 days, 2 WNV)
- San Luis Obispo County: February 22 to November 21 (272 days, 6 WNV)
West Nile in Yuba County
From 1999 to 2025, CDC ArboNET counted 72 human West Nile cases in Yuba County (38 neuroinvasive) across 14 years. The worst was 2013 with 13; the latest was 2024.
More: how the dates are worked out · reading the West Nile counts.