Plant By Frost

Washington

Frost dates for Plain, WA

At this NOAA station the last spring frost (32°F) usually comes by May 22 and the first fall frost around September 22, giving a growing season of about 121 days.

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

Frost odds

1 year in 10 the last spring frost is later thanJune 13
Half of years the last spring frost is later thanMay 22
9 years in 10 the last spring frost is later thanMay 2
1 year in 10 the first fall frost is earlier thanSeptember 7
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 3 and returns around October 4.

A light frost (36°F, which can still nip tender plants) usually ends by June 13 and returns around September 8.

Station USC00456534, elevation 590 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.

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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