Frost Report

All states Montana

Frost dates for Outlook, 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 28

typical year

Safe to plant

June 13

frost is over in 9 of 10 years

First fall frost

September 7

typical year

Growing season

101 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 30 – May 14 –
Spinach – Apr 16 – May 7 Jul 13 – 27
Lettuce – Apr 30 – May 21 Jul 13 – 27
Radishes – Apr 30 – Jun 11 Jul 27 – Aug 10
Onions – Apr 30 – May 14 –
Potatoes Season usually too short. Try a quick variety or row covers.
Carrots – May 7 – 28 Jun 15 – 29
Beets – Apr 30 – May 14 Jun 29 – Jul 13
Kale Mar 19 – Apr 2 Apr 30 – May 14 Jun 29 – Jul 13
Broccoli Mar 19 – Apr 2 May 14 – 28 Jun 29 – Jul 13
Cabbage Mar 5 – 19 Apr 30 – May 14 Jun 29 – Jul 13
Garlic – – Jul 27 – Aug 17
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 – 29 –
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 28May 15
Fall frost before August 22September 7September 19

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 18 (May 31 in a late year), and the first one in fall around September 16.

Towns that use these dates

This is the nearest NOAA station with frost records for 2 towns.

Outlook, Flaxville

Where these dates come from

NOAA weather station REDSTONE, MT US (USC00246927), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 13 miles:

59222, 59252, 59257

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