Plant By Frost

Montana

Frost dates for Miles City F Wiley Fld, MT

At this NOAA station the last spring frost (32°F) usually comes by May 8 and the first fall frost around September 30, giving a growing season of about 144 days.

May 8average last spring frost
September 30average first fall frost
JanAprJulOctDec

Frost odds

1 year in 10 the last spring frost is later thanMay 21
Half of years the last spring frost is later thanMay 8
9 years in 10 the last spring frost is later thanApril 26
1 year in 10 the first fall frost is earlier thanSeptember 17
Half of years the first fall frost is earlier thanSeptember 30
9 years in 10 the first fall frost is earlier thanOctober 14

A hard freeze (28°F) usually ends by April 29 and returns around October 8.

A light frost (36°F, which can still nip tender plants) usually ends by May 18 and returns around September 23.

Station USW00024037, elevation 800 m. Based on 30 years of 1991 to 2020 records. A garden higher up, in a hollow or far from this station can freeze later in spring.

Check another ZIP

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