Mosquito season in Johnson County, AR: when it starts and ends
Mosquito months in Johnson County
In a normal year mosquito season in Johnson County, AR starts around March 14 and ends around November 15, about 35 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Johnson County, and when
- Start tipping out standing water weekly by February 28.
- Book any yard treatment for mid March, ahead of the July peak.
- Repellent can go away after November 15.
- 2 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to September, more so if over 60.
Johnson County against the rest of AR
Johnson County has the 41st longest season of 75 AR counties, at 246 days against 274 in Chicot County and 211 in Washington County. Its mean temperature is 60°F.
- Jackson County: March 13 to November 14 (246 days, 0 WNV)
- Pope County: March 13 to November 14 (246 days, 2 WNV)
- Logan County: March 14 to November 15 (246 days, 0 WNV)
- Conway County: March 14 to November 14 (245 days, 1 WNV)
West Nile in Johnson County
From 1999 to 2025, CDC ArboNET counted 3 human West Nile cases in Johnson County (3 neuroinvasive) across 3 years. The worst was 2025 with 1; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.