Frost Report

All states Idaho

Frost dates for Small, 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

June 5

typical year

Safe to plant

June 21

frost is over in 9 of 10 years

First fall frost

September 20

typical year

Growing season

106 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 8 – 22 –
Spinach – Apr 24 – May 15 Jul 26 – Aug 9
Lettuce – May 8 – 29 Jul 26 – Aug 9
Radishes – May 8 – Jun 19 Aug 9 – 23
Onions – May 8 – 22 –
Potatoes – May 15 – 29 –
Carrots – May 15 – Jun 5 Jun 28 – Jul 12
Beets – May 8 – 22 Jul 12 – 26
Kale Mar 27 – Apr 10 May 8 – 22 Jul 12 – 26
Broccoli Mar 27 – Apr 10 May 22 – Jun 5 Jul 12 – 26
Cabbage Mar 13 – 27 May 8 – 22 Jul 12 – 26
Garlic – – Aug 9 – 30
Warm-season crops
Tomatoes Apr 26 – May 10 Jun 21 – Jul 5 –
Peppers Apr 19 – May 3 Jun 28 – Jul 12 –
Cucumbers – Jun 21 – Jul 12 –
Zucchini – Jun 21 – Jul 19 –
Pumpkins Season usually too short. Try a quick variety or row covers.
Green beans – Jun 21 – Jul 12 –
Sweet corn – Jun 21 – Jul 19 –
Basil May 17 – 31 Jun 28 – Jul 5 –

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 21June 5May 11
Fall frost before September 3September 20October 4

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 10 (June 8 in a late year), and the first one in fall around October 2.

Where these dates come from

NOAA weather station SMALL 6N, ID US (USC00108500), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 5 miles:

83423

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