Mosquito season in Kent County, DE: when it starts and ends

Mosquito months in Kent County

In a normal year mosquito season in Kent County, DE starts around March 30 and ends around November 11, about 32 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 Kent County, and when

• Start tipping out standing water weekly by March 16.
• Book any yard treatment for late March, ahead of the July peak.
• Repellent can go away after November 11.
• 4 West Nile cases since 2016 (last 2021): you should use repellent at dusk June to September, more so if over 60.

Kent County against the rest of DE

Kent County has the 2nd longest season of 3 DE counties, at 226 days against 230 in Sussex County and 215 in New Castle County. Its mean temperature is 57.1°F.

• Sussex County: March 28 to November 13 (230 days, 6 WNV)
• New Castle County: April 4 to November 5 (215 days, 14 WNV)

West Nile in Kent County

From 1999 to 2025, CDC ArboNET counted 20 human West Nile cases in Kent County (9 neuroinvasive) across 10 years. The worst was 2003 with 8; the latest was 2021.

See how the dates are worked out, and reading the West Nile counts.