Frost Report

All states Montana

Frost dates for Powderville, 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 13

typical year

Safe to plant

May 31

frost is over in 9 of 10 years

First fall frost

September 25

typical year

Growing season

132 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 15 – 29 –
Spinach – Apr 1 – 22 Jul 31 – Aug 14
Lettuce – Apr 15 – May 6 Jul 31 – Aug 14
Radishes – Apr 15 – May 27 Aug 14 – 28
Onions – Apr 15 – 29 –
Potatoes – Apr 22 – May 6 –
Carrots – Apr 22 – May 13 Jul 3 – 17
Beets – Apr 15 – 29 Jul 17 – 31
Kale Mar 4 – 18 Apr 15 – 29 Jul 17 – 31
Broccoli Mar 4 – 18 Apr 29 – May 13 Jul 17 – 31
Cabbage Feb 18 – Mar 4 Apr 15 – 29 Jul 17 – 31
Garlic – – Aug 14 – Sep 4
Warm-season crops
Tomatoes Apr 5 – 19 May 31 – Jun 14 –
Peppers Mar 29 – Apr 12 Jun 7 – 21 –
Cucumbers – May 31 – Jun 21 –
Zucchini – May 31 – Jun 28 –
Pumpkins – May 31 – Jun 21 –
Green beans – May 31 – Jul 17 –
Sweet corn – May 31 – Jun 28 –
Basil Apr 26 – May 10 Jun 7 – 14 –

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 May 31May 13May 1
Fall frost before September 6September 25October 9

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 2 (May 22 in a late year), and the first one in fall around October 4.

Where these dates come from

NOAA weather station POWDERVILLE 8 NNE, MT US (USC00246691), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 9 miles:

59345

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