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

Mosquito months in Santa Fe County

In a normal year mosquito season in Santa Fe County, NM starts around May 3 and ends around October 16, about 24 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 Santa Fe County, and when

• Start tipping out standing water weekly by April 19.
• Book any yard treatment for early May, ahead of the July peak.
• Repellent can go away after October 16.
• 14 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to July, and check NM spray notices.

Santa Fe County against the rest of NM

Santa Fe County has the 24th longest season of 33 NM counties, at 166 days against 268 in Doña Ana County and 114 in Catron County. Its mean temperature is 50.8°F.

• Sandoval County: April 26 to October 20 (177 days, 18 WNV)
• Union County: April 26 to October 17 (174 days, 4 WNV)
• Torrance County: May 5 to October 10 (158 days, 3 WNV)
• Colfax County: May 5 to October 8 (156 days, 1 WNV)

West Nile in Santa Fe County

From 1999 to 2025, CDC ArboNET counted 36 human West Nile cases in Santa Fe County (24 neuroinvasive) across 11 years. The worst was 2003 with 12; the latest was 2025.

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