Mosquito season in Solano County, CA: when it starts and ends
Mosquito months in Solano County
In a normal year mosquito season in Solano County, CA starts around January 28 and ends around December 7, about 45 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Solano County, and when
- Start tipping out standing water weekly by January 14.
- Book any yard treatment for late January, ahead of the July peak.
- Repellent can go away after December 7.
- 18 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to September, and check CA spray notices.
Solano County against the rest of CA
Solano County has the 13th longest season of 58 CA counties, at 313 days against 365 in Los Angeles County and 110 in Mono County. Its mean temperature is 62.3°F.
- Kern County: January 25 to December 8 (316 days, 173 WNV)
- San Joaquin County: January 27 to December 7 (314 days, 86 WNV)
- San Bernardino County: January 30 to December 8 (312 days, 122 WNV)
- Sacramento County: January 29 to December 5 (310 days, 131 WNV)
West Nile in Solano County
From 1999 to 2025, CDC ArboNET counted 42 human West Nile cases in Solano County (25 neuroinvasive) across 16 years. The worst was 2006 with 8; the latest was 2025.
See how the dates are worked out, and reading the West Nile counts.