Frost Report

All states Idaho

Frost dates for Richfield, 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 24

typical year

Safe to plant

June 14

frost is over in 9 of 10 years

First fall frost

September 26

typical year

Growing season

123 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 26 – May 10 –
Spinach – Apr 12 – May 3 Aug 1 – 15
Lettuce – Apr 26 – May 17 Aug 1 – 15
Radishes – Apr 26 – Jun 7 Aug 15 – 29
Onions – Apr 26 – May 10 –
Potatoes – May 3 – 17 –
Carrots – May 3 – 24 Jul 4 – 18
Beets – Apr 26 – May 10 Jul 18 – Aug 1
Kale Mar 15 – 29 Apr 26 – May 10 Jul 18 – Aug 1
Broccoli Mar 15 – 29 May 10 – 24 Jul 18 – Aug 1
Cabbage Mar 1 – 15 Apr 26 – May 10 Jul 18 – Aug 1
Garlic – – Aug 15 – Sep 5
Warm-season crops
Tomatoes Apr 19 – May 3 Jun 14 – 28 –
Peppers Apr 12 – 26 Jun 21 – Jul 5 –
Cucumbers – Jun 14 – Jul 5 –
Zucchini – Jun 14 – Jul 12 –
Pumpkins – Jun 14 – Jul 5 –
Green beans – Jun 14 – Jul 18 –
Sweet corn – Jun 14 – Jul 12 –
Basil May 10 – 24 Jun 21 – 28 –

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 14May 24May 6
Fall frost before September 10September 26October 10

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 8 (May 28 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.

Richfield

Where these dates come from

NOAA weather station RICHFIELD, ID US (USC00107673), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 5 miles:

83349

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