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

Mosquito months in San Miguel County

In a normal year mosquito season in San Miguel County, NM starts around May 10 and ends around October 7, about 21 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 San Miguel County, and when

• Start tipping out standing water weekly by April 26.
• Book any yard treatment for early May, ahead of the July peak.
• Repellent can go away after October 7.
• 4 West Nile cases since 2016 (last 2023): you should use repellent at dusk July, more so if over 60.

San Miguel County against the rest of NM

San Miguel County has the 27th longest season of 33 NM counties, at 150 days against 268 in Doña Ana County and 114 in Catron County. Its mean temperature is 49.8°F.

• Torrance County: May 5 to October 10 (158 days, 3 WNV)
• Colfax County: May 5 to October 8 (156 days, 1 WNV)
• Mora County: May 11 to October 3 (145 days, 1 WNV)
• McKinley County: May 15 to October 3 (141 days, 3 WNV)

West Nile in San Miguel County

From 1999 to 2025, CDC ArboNET counted 12 human West Nile cases in San Miguel County (4 neuroinvasive) across 3 years. The worst was 2003 with 7; the latest was 2023.

Background: reading the West Nile counts; how the dates are worked out.