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

Mosquito months in Honolulu County

Mosquitoes in Honolulu County, HI can be active in any month. The worst stretch is January to December.

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 Honolulu County, and when

• No off-season here: tip out standing water every week, all year.
• A yard treatment matters most January to December.
• 1 West Nile case since 2016 (last 2024): you should use repellent at dusk January to December, more so if over 60.

Honolulu County against the rest of HI

Honolulu County has the 1st longest season of 5 HI counties, at 365 days against 365 in Honolulu County and 272 in Hawaii County. Its mean temperature is 75.1°F.

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

West Nile in Honolulu County

From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Honolulu County (1 neuroinvasive) across 2 years. The worst was 2024 with 1; the latest was 2024.

See how the dates are worked out, and where mosquitoes never stop.