Frost Report

All states Montana

Frost dates for Lavina, 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 22

typical year

Safe to plant

June 4

frost is over in 9 of 10 years

First fall frost

September 15

typical year

Growing season

114 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 24 – May 8 –
Spinach – Apr 10 – May 1 Jul 21 – Aug 4
Lettuce – Apr 24 – May 15 Jul 21 – Aug 4
Radishes – Apr 24 – Jun 5 Aug 4 – 18
Onions – Apr 24 – May 8 –
Potatoes – May 1 – 15 –
Carrots – May 1 – 22 Jun 23 – Jul 7
Beets – Apr 24 – May 8 Jul 7 – 21
Kale Mar 13 – 27 Apr 24 – May 8 Jul 7 – 21
Broccoli Mar 13 – 27 May 8 – 22 Jul 7 – 21
Cabbage Feb 27 – Mar 13 Apr 24 – May 8 Jul 7 – 21
Garlic – – Aug 4 – 25
Warm-season crops
Tomatoes Apr 9 – 23 Jun 4 – 18 –
Peppers Apr 2 – 16 Jun 11 – 25 –
Cucumbers – Jun 4 – 25 –
Zucchini – Jun 4 – Jul 2 –
Pumpkins – Jun 4 – 25 –
Green beans – Jun 4 – Jul 7 –
Sweet corn – Jun 4 – Jul 2 –
Basil Apr 30 – May 14 Jun 11 – 18 –

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 4May 22May 11
Fall frost before August 31September 15September 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 11 (May 22 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 2 towns.

Lavina, Broadview

Where these dates come from

NOAA weather station ROUNDUP 15 SW, MT US (USC00247220), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 18 miles:

59015, 59046

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