Frost Report

All states Montana

Frost dates for Deer Lodge, 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

June 9

typical year

Safe to plant

June 26

frost is over in 9 of 10 years

First fall frost

September 8

typical year

Growing season

91 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 – May 12 – 26 –
Spinach – Apr 28 – May 19 Jul 14 – 28
Lettuce – May 12 – Jun 2 Jul 14 – 28
Radishes – May 12 – Jun 23 Jul 28 – Aug 11
Onions – May 12 – 26 –
Potatoes Season usually too short. Try a quick variety or row covers.
Carrots – May 19 – Jun 9 Jun 16 – 30
Beets – May 12 – 26 Jun 30 – Jul 14
Kale Mar 31 – Apr 14 May 12 – 26 Jun 30 – Jul 14
Broccoli Mar 31 – Apr 14 May 26 – Jun 9 Jun 30 – Jul 14
Cabbage Mar 17 – 31 May 12 – 26 Jun 30 – Jul 14
Garlic – – Jul 28 – Aug 18
Warm-season crops
Tomatoes Season usually too short. Try a quick variety or row covers.
Peppers Season usually too short. Try a quick variety or row covers.
Cucumbers – Jun 26 – Jul 17 –
Zucchini – Jun 26 – Jul 24 –
Pumpkins Season usually too short. Try a quick variety or row covers.
Green beans – Jun 26 – 30 –
Sweet corn Season usually too short. Try a quick variety or row covers.
Basil May 22 – Jun 5 Jul 3 – 10 –

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 26June 9May 23
Fall frost before August 26September 8September 21

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 16 (June 3 in a late year), and the first one in fall around September 20.

Towns that use these dates

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

Deer Lodge, Drummond

Where these dates come from

NOAA weather station ELLISTON, MT US (USC00242738), 1991–2020 climate normals. It's the nearest station for 5 zip codes, all within 34 miles:

59713, 59728, 59731, 59733, 59843

1 of these zip codes are more than 30 miles from the station, so their real frost dates may differ by a week or more.

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