Frost Report

All states Alaska

Frost dates for Sterling, 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

May 20

typical year

Safe to plant

June 1

frost is over in 9 of 10 years

First fall frost

September 21

typical year

Growing season

123 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 – Apr 22 – May 6 –
Spinach – Apr 8 – 29 Jul 27 – Aug 10
Lettuce – Apr 22 – May 13 Jul 27 – Aug 10
Radishes – Apr 22 – Jun 3 Aug 10 – 24
Onions – Apr 22 – May 6 –
Potatoes – Apr 29 – May 13 –
Carrots – Apr 29 – May 20 Jun 29 – Jul 13
Beets – Apr 22 – May 6 Jul 13 – 27
Kale Mar 11 – 25 Apr 22 – May 6 Jul 13 – 27
Broccoli Mar 11 – 25 May 6 – 20 Jul 13 – 27
Cabbage Feb 25 – Mar 11 Apr 22 – May 6 Jul 13 – 27
Garlic – – Aug 10 – 31
Warm-season crops
Tomatoes Apr 6 – 20 Jun 1 – 15 –
Peppers Mar 30 – Apr 13 Jun 8 – 22 –
Cucumbers – Jun 1 – 22 –
Zucchini – Jun 1 – 29 –
Pumpkins – Jun 1 – 22 –
Green beans – Jun 1 – Jul 13 –
Sweet corn – Jun 1 – 29 –
Basil Apr 27 – May 11 Jun 8 – 15 –

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 June 1May 20May 6
Fall frost before September 6September 21October 4

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 3 (May 17 in a late year), and the first one in fall around September 30.

Where these dates come from

NOAA weather station STERLING 6SW, AK US (USC00508731), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 19 miles:

99568, 99672

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