Frost Report

All states Idaho

Frost dates for Fairfield, 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 8

typical year

Safe to plant

June 28

frost is over in 9 of 10 years

First fall frost

September 14

typical year

Growing season

97 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 11 – 25 –
Spinach – Apr 27 – May 18 Jul 20 – Aug 3
Lettuce – May 11 – Jun 1 Jul 20 – Aug 3
Radishes – May 11 – Jun 22 Aug 3 – 17
Onions – May 11 – 25 –
Potatoes Season usually too short. Try a quick variety or row covers.
Carrots – May 18 – Jun 8 Jun 22 – Jul 6
Beets – May 11 – 25 Jul 6 – 20
Kale Mar 30 – Apr 13 May 11 – 25 Jul 6 – 20
Broccoli Mar 30 – Apr 13 May 25 – Jun 8 Jul 6 – 20
Cabbage Mar 16 – 30 May 11 – 25 Jul 6 – 20
Garlic – – Aug 3 – 24
Warm-season crops
Tomatoes May 3 – 17 Jun 28 – Jul 12 –
Peppers Season usually too short. Try a quick variety or row covers.
Cucumbers – Jun 28 – Jul 19 –
Zucchini – Jun 28 – Jul 26 –
Pumpkins Season usually too short. Try a quick variety or row covers.
Green beans – Jun 28 – Jul 6 –
Sweet corn Season usually too short. Try a quick variety or row covers.
Basil May 24 – Jun 7 Jul 5 – 12 –

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 28June 8May 15
Fall frost before August 29September 14September 28

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 11 (June 7 in a late year), and the first one in fall around September 28.

Towns that use these dates

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

Fairfield

Where these dates come from

NOAA weather station FAIRFIELD RS, ID US (USC00103108), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 11 miles:

83327

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