Frost Report

All states Montana

Frost dates for Wibaux, MT

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 27

typical year

Safe to plant

June 13

frost is over in 9 of 10 years

First fall frost

September 16

typical year

Growing season

112 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 29 – May 13 –
Spinach – Apr 15 – May 6 Jul 22 – Aug 5
Lettuce – Apr 29 – May 20 Jul 22 – Aug 5
Radishes – Apr 29 – Jun 10 Aug 5 – 19
Onions – Apr 29 – May 13 –
Potatoes – May 6 – 20 –
Carrots – May 6 – 27 Jun 24 – Jul 8
Beets – Apr 29 – May 13 Jul 8 – 22
Kale Mar 18 – Apr 1 Apr 29 – May 13 Jul 8 – 22
Broccoli Mar 18 – Apr 1 May 13 – 27 Jul 8 – 22
Cabbage Mar 4 – 18 Apr 29 – May 13 Jul 8 – 22
Garlic – – Aug 5 – 26
Warm-season crops
Tomatoes Apr 18 – May 2 Jun 13 – 27 –
Peppers Apr 11 – 25 Jun 20 – Jul 4 –
Cucumbers – Jun 13 – Jul 4 –
Zucchini – Jun 13 – Jul 11 –
Pumpkins Season usually too short. Try a quick variety or row covers.
Green beans – Jun 13 – Jul 8 –
Sweet corn – Jun 13 – Jul 11 –
Basil May 9 – 23 Jun 20 – 27 –

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 13May 27May 15
Fall frost before September 2September 16September 29

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 17 (June 1 in a late year), and the first one in fall around September 26.

Towns that use these dates

This is the nearest NOAA station with frost records for 1 town.

Wibaux

Where these dates come from

NOAA weather station WIBAUX 2 E, MT US (USC00248957), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 6 miles:

59353

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