Plant By Frost

Alaska

Frost dates for Port Alcan, AK

At this NOAA station the last spring frost (32°F) usually comes by May 28 and the first fall frost around August 29, giving a growing season of about 91 days.

May 28average last spring frost
August 29average first fall frost
JanAprJulOctDec

Frost odds

1 year in 10 the last spring frost is later thanJune 10
Half of years the last spring frost is later thanMay 28
9 years in 10 the last spring frost is later thanMay 15
1 year in 10 the first fall frost is earlier thanAugust 14
Half of years the first fall frost is earlier thanAugust 29
9 years in 10 the first fall frost is earlier thanSeptember 8

A hard freeze (28°F) usually ends by May 15 and returns around September 9.

Station USC00507513, elevation 577 m. Based on 24 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