Frost Report

All states Idaho

Frost dates for Rexburg, ID

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 12

typical year

Safe to plant

June 2

frost is over in 9 of 10 years

First fall frost

September 24

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 14 – 28 –
Spinach – Mar 31 – Apr 21 Jul 30 – Aug 13
Lettuce – Apr 14 – May 5 Jul 30 – Aug 13
Radishes – Apr 14 – May 26 Aug 13 – 27
Onions – Apr 14 – 28 –
Potatoes – Apr 21 – May 5 –
Carrots – Apr 21 – May 12 Jul 2 – 16
Beets – Apr 14 – 28 Jul 16 – 30
Kale Mar 3 – 17 Apr 14 – 28 Jul 16 – 30
Broccoli Mar 3 – 17 Apr 28 – May 12 Jul 16 – 30
Cabbage Feb 17 – Mar 3 Apr 14 – 28 Jul 16 – 30
Garlic – – Aug 13 – Sep 3
Warm-season crops
Tomatoes Apr 7 – 21 Jun 2 – 16 –
Peppers Mar 31 – Apr 14 Jun 9 – 23 –
Cucumbers – Jun 2 – 23 –
Zucchini – Jun 2 – 30 –
Pumpkins – Jun 2 – 23 –
Green beans – Jun 2 – Jul 16 –
Sweet corn – Jun 2 – 30 –
Basil Apr 28 – May 12 Jun 9 – 16 –

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 2May 12April 29
Fall frost before September 6September 24October 8

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 April 30 (May 14 in a late year), and the first one in fall around October 7.

Towns that use these dates

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

Rexburg

Where these dates come from

NOAA weather station REXBURG BYU IDAHO, ID US (USC00107644), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 1 miles:

83440, 83460

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