Mosquito season in Chaves County, NM: when it starts and ends

Mosquito months in Chaves County

In a normal year mosquito season in Chaves County, NM starts around March 31 and ends around November 6, about 31 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 Chaves County, and when

• Start tipping out standing water weekly by March 17.
• Book any yard treatment for late March, ahead of the July peak.
• Repellent can go away after November 6.
• 9 West Nile cases since 2016 (last 2025): you should use repellent at dusk June to September, more so if over 60.

Chaves County against the rest of NM

Chaves County has the 7th longest season of 33 NM counties, at 220 days against 268 in Doña Ana County and 114 in Catron County. Its mean temperature is 60.8°F.

• Hidalgo County: March 11 to November 18 (252 days, 0 WNV)
• Luna County: March 16 to November 13 (242 days, 5 WNV)
• Socorro County: March 31 to November 3 (217 days, 1 WNV)
• Bernalillo County: March 31 to November 1 (215 days, 87 WNV)

West Nile in Chaves County

From 1999 to 2025, CDC ArboNET counted 33 human West Nile cases in Chaves County (20 neuroinvasive) across 10 years. The worst was 2003 with 8; the latest was 2025.

More: how the dates are worked out · reading the West Nile counts.