Mosquito season in Hawaii County, HI: when it starts and ends

Mosquito months in Hawaii County

In a normal year mosquito season in Hawaii County, HI starts around March 26 and ends around December 23, about 39 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Hawaii County, and when

• Start tipping out standing water weekly by March 12.
• Book any yard treatment for late March, ahead of the August peak.
• Repellent can go away after December 23.
• No West Nile cases since 2016, so bites in Hawaii County are a nuisance; check window screens.

Hawaii County against the rest of HI

Hawaii County has the 5th longest season of 5 HI counties, at 272 days against 365 in Honolulu County and 272 in Hawaii County. Its mean temperature is 52.4°F.

• Kauai County: all year (365 days, 0 WNV)
• Maui County: all year (365 days, 0 WNV)

West Nile in Hawaii County

CDC ArboNET lists no human West Nile cases for Hawaii County from 1999 to 2025.

See how the dates are worked out, and when mosquitoes go away for the winter.