Frost Report

All states Alaska

Frost dates for Cooper Landing, AK

When the last spring frost and first fall frost usually come, and when to plant, from 30 years of NOAA weather records.

Last spring frost

June 12

typical year

Safe to plant

July 2

frost is over in 9 of 10 years

First fall frost

September 1

typical year

Growing season

78 days

frost-free, typical year

When to plant

Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.

CropStart indoorsPlant outsideFall planting
Cool-season crops
Peas – May 15 – 29 –
Spinach – May 1 – 22 Jul 7 – 21
Lettuce – May 15 – Jun 5 Jul 7 – 21
Radishes – May 15 – Jun 26 Jul 21 – Aug 4
Onions – May 15 – 29 –
Potatoes Season usually too short. Try a quick variety or row covers.
Carrots – May 22 – Jun 12 Jun 9 – 23
Beets – May 15 – 29 Jun 23 – Jul 7
Kale Apr 3 – 17 May 15 – 29 Jun 23 – Jul 7
Broccoli Apr 3 – 17 May 29 – Jun 12 Jun 23 – Jul 7
Cabbage Mar 20 – Apr 3 May 15 – 29 Jun 23 – Jul 7
Garlic – – Jul 21 – Aug 11
Warm-season crops
Tomatoes Season usually too short. Try a quick variety or row covers.
Peppers Season usually too short. Try a quick variety or row covers.
Cucumbers – Jul 2 – 23 –
Zucchini – Jul 2 – 30 –
Pumpkins Season usually too short. Try a quick variety or row covers.
Green beans Season usually too short. Try a quick variety or row covers.
Sweet corn Season usually too short. Try a quick variety or row covers.
Basil May 28 – Jun 11 Jul 9 – 16 –

Onions: from sets. Green beans: until 10 weeks before the first fall frost. Garlic: harvest next summer.

The year at a glance

Start indoors Plant outside Fall planting

The chance of frost, by date

1 year in 10Half of years9 years in 10
Spring frost after July 2June 12May 29
Fall frost before August 14September 1September 17

Frost here means 32°F or colder. Read across: in 1 year in 10, spring frost carries on past the first date, which is why that date is the safe-to-plant date.

Hard freeze (28°F)

A hard freeze kills most garden plants, even hardy ones. The last one in spring usually comes around May 26 (June 8 in a late year), and the first one in fall around September 15.

Where these dates come from

NOAA weather station COOPER LANDING 5 W, AK US (USC00502149), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 11 miles:

99572, 99631

Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.