Frost Report

All states Idaho

Frost dates for Dubois, 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 18

typical year

Safe to plant

June 9

frost is over in 9 of 10 years

First fall frost

September 30

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 20 – May 4 –
Spinach – Apr 6 – 27 Aug 5 – 19
Lettuce – Apr 20 – May 11 Aug 5 – 19
Radishes – Apr 20 – Jun 1 Aug 19 – Sep 2
Onions – Apr 20 – May 4 –
Potatoes – Apr 27 – May 11 –
Carrots – Apr 27 – May 18 Jul 8 – 22
Beets – Apr 20 – May 4 Jul 22 – Aug 5
Kale Mar 9 – 23 Apr 20 – May 4 Jul 22 – Aug 5
Broccoli Mar 9 – 23 May 4 – 18 Jul 22 – Aug 5
Cabbage Feb 23 – Mar 9 Apr 20 – May 4 Jul 22 – Aug 5
Garlic – – Aug 19 – Sep 9
Warm-season crops
Tomatoes Apr 14 – 28 Jun 9 – 23 –
Peppers Apr 7 – 21 Jun 16 – 30 –
Cucumbers – Jun 9 – 30 –
Zucchini – Jun 9 – Jul 7 –
Pumpkins – Jun 9 – 30 –
Green beans – Jun 9 – Jul 22 –
Sweet corn – Jun 9 – Jul 7 –
Basil May 5 – 19 Jun 16 – 23 –

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 9May 18May 3
Fall frost before September 14September 30October 16

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 17 in a late year), and the first one in fall around October 12.

Towns that use these dates

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

Dubois, Spencer

Where these dates come from

NOAA weather station DUBOIS EXP STN, ID US (USC00102707), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 8 miles:

83446

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