Mosquito season in Converse County, WY: when it starts and ends
Mosquito months in Converse County
In a normal year mosquito season in Converse County, WY starts around May 8 and ends around October 1, about 21 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Converse County, and when
- Start tipping out standing water weekly by April 24.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 1.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk July to July, more so if over 60.
Converse County against the rest of WY
Converse County has the 6th longest season of 23 WY counties, at 146 days against 163 in Big Horn County and 75 in Teton County. Its mean temperature is 46.4°F.
- Niobrara County: May 5 to October 5 (153 days, 0 WNV)
- Sheridan County: May 8 to October 5 (150 days, 3 WNV)
- Weston County: May 9 to October 2 (146 days, 0 WNV)
- Goshen County: May 9 to October 1 (145 days, 15 WNV)
West Nile in Converse County
From 1999 to 2025, CDC ArboNET counted 25 human West Nile cases in Converse County (9 neuroinvasive) across 6 years. The worst was 2003 with 19; the latest was 2025.
More: how the dates are worked out · when the season starts across the US.