Frost Report

All states North Dakota

Frost dates for Williston, ND

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 21

typical year

Safe to plant

June 3

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 23 – May 7 –
Spinach – Apr 9 – 30 Jul 27 – Aug 10
Lettuce – Apr 23 – May 14 Jul 27 – Aug 10
Radishes – Apr 23 – Jun 4 Aug 10 – 24
Onions – Apr 23 – May 7 –
Potatoes – Apr 30 – May 14 –
Carrots – Apr 30 – May 21 Jun 29 – Jul 13
Beets – Apr 23 – May 7 Jul 13 – 27
Kale Mar 12 – 26 Apr 23 – May 7 Jul 13 – 27
Broccoli Mar 12 – 26 May 7 – 21 Jul 13 – 27
Cabbage Feb 26 – Mar 12 Apr 23 – May 7 Jul 13 – 27
Garlic – – Aug 10 – 31
Warm-season crops
Tomatoes Apr 8 – 22 Jun 3 – 17 –
Peppers Apr 1 – 15 Jun 10 – 24 –
Cucumbers – Jun 3 – 24 –
Zucchini – Jun 3 – Jul 1 –
Pumpkins – Jun 3 – 24 –
Green beans – Jun 3 – Jul 13 –
Sweet corn – Jun 3 – Jul 1 –
Basil Apr 29 – May 13 Jun 10 – 17 –

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 3May 21May 8
Fall frost before September 9September 21October 2

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 11 (May 25 in a late year), and the first one in fall around September 28.

Towns that use these dates

This is the nearest NOAA station with frost records for 3 towns.

Williston, Epping, Springbrook

Where these dates come from

NOAA weather station WILLISTON SLOULIN INTL AP, ND US (USW00094014), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 13 miles:

58843

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