Frost Report

All states Idaho

Frost dates for Bruneau, 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

April 17

typical year

Safe to plant

May 7

frost is over in 9 of 10 years

First fall frost

October 17

typical year

Growing season

181 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 – Mar 20 – Apr 3 –
Spinach – Mar 6 – 27 Aug 22 – Sep 5
Lettuce – Mar 20 – Apr 10 Aug 22 – Sep 5
Radishes – Mar 20 – May 1 Sep 5 – 19
Onions – Mar 20 – Apr 3 –
Potatoes – Mar 27 – Apr 10 –
Carrots – Mar 27 – Apr 17 Jul 25 – Aug 8
Beets – Mar 20 – Apr 3 Aug 8 – 22
Kale Feb 6 – 20 Mar 20 – Apr 3 Aug 8 – 22
Broccoli Feb 6 – 20 Apr 3 – 17 Aug 8 – 22
Cabbage Jan 23 – Feb 6 Mar 20 – Apr 3 Aug 8 – 22
Garlic – – Sep 5 – 26
Warm-season crops
Tomatoes Mar 12 – 26 May 7 – 21 –
Peppers Mar 5 – 19 May 14 – 28 –
Cucumbers – May 7 – 28 –
Zucchini – May 7 – Jun 4 –
Pumpkins – May 7 – 28 –
Green beans – May 7 – Aug 8 –
Sweet corn – May 7 – Jun 4 –
Basil Apr 2 – 16 May 14 – 21 –

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 May 7April 17March 31
Fall frost before October 1October 17November 1

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 March 30 (April 18 in a late year), and the first one in fall around October 31.

Where these dates come from

NOAA weather station BRUNEAU, ID US (USC00101195), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 11 miles:

83604

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