Mosquito season in Jerome County, ID: when it starts and ends
Mosquito months in Jerome County
In a normal year mosquito season in Jerome County, ID starts around April 25 and ends around October 14, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jerome County, and when
- Start tipping out standing water weekly by April 11.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 14.
- No West Nile cases since 2016, so bites in Jerome County are a nuisance; check window screens.
Jerome County against the rest of ID
Jerome County has the 6th longest season of 44 ID counties, at 172 days against 194 in Canyon County and 85 in Fremont County. Its mean temperature is 49.2°F.
- Gooding County: April 19 to October 15 (179 days, 9 WNV)
- Nez Perce County: April 22 to October 14 (175 days, 0 WNV)
- Twin Falls County: April 26 to October 13 (171 days, 10 WNV)
- Power County: April 26 to October 11 (168 days, 0 WNV)
West Nile in Jerome County
From 1999 to 2025, CDC ArboNET counted 16 human West Nile cases in Jerome County (2 neuroinvasive) across 5 years. The worst was 2006 with 12; the latest was 2014.
More: how the dates are worked out · when the season starts across the US.