Plant By Frost

Wyoming

Frost dates for Douglas Converse Co Airport, WY

At this NOAA station the last spring frost (32°F) usually comes by May 23 and the first fall frost around September 22, giving a growing season of about 122 days.

May 23average last spring frost
September 22average first fall frost
JanAprJulOctDec

Frost odds

1 year in 10 the last spring frost is later thanJune 7
Half of years the last spring frost is later thanMay 23
9 years in 10 the last spring frost is later thanMay 10
1 year in 10 the first fall frost is earlier thanSeptember 9
Half of years the first fall frost is earlier thanSeptember 22
9 years in 10 the first fall frost is earlier thanOctober 4

A hard freeze (28°F) usually ends by May 8 and returns around October 1.

A light frost (36°F, which can still nip tender plants) usually ends by June 5 and returns around September 12.

Station USW00094057, elevation 1502 m. Based on 21 years of 1991 to 2020 records. A garden higher up, in a hollow or far from this station can freeze later in spring.

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Sources

  1. U.S. Annual/Seasonal Climate Normals, 1991 to 2020 (freeze probability dates by station), NOAA National Centers for Environmental Information, checked 1 November 2026
  2. Annual/Seasonal Normals 1991 to 2020 documentation, NOAA National Centers for Environmental Information, checked 1 November 2026
  3. 2024 Gazetteer Files, ZIP Code Tabulation Areas, US Census Bureau, checked 1 November 2026