Mosquito season in Mono County, CA: when it starts and ends
Mosquito months in Mono County
In a normal year mosquito season in Mono County, CA starts around June 4 and ends around September 22, about 16 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Mono County, and when
- Start tipping out standing water weekly by May 21.
- Book any yard treatment for early June, ahead of the July peak.
- Repellent can go away after September 22.
- No West Nile cases since 2016, so bites in Mono County are a nuisance; check window screens.
Mono County against the rest of CA
Mono County has the 58th longest season of 58 CA counties, at 110 days against 365 in Los Angeles County and 110 in Mono County. Its mean temperature is 41°F.
- Alpine County: May 28 to October 3 (128 days, 0 WNV)
- Lassen County: May 30 to October 1 (124 days, 0 WNV)
West Nile in Mono County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Mono County (1 neuroinvasive) across 1 year. The worst was 2006 with 1; the latest was 2006.
See how the dates are worked out, and when the season starts across the US.