Frost Report

All states Idaho

Frost dates for Hamer, 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 3

typical year

Safe to plant

June 21

frost is over in 9 of 10 years

First fall frost

September 11

typical year

Growing season

98 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 6 – 20 –
Spinach – Apr 22 – May 13 Jul 17 – 31
Lettuce – May 6 – 27 Jul 17 – 31
Radishes – May 6 – Jun 17 Jul 31 – Aug 14
Onions – May 6 – 20 –
Potatoes Season usually too short. Try a quick variety or row covers.
Carrots – May 13 – Jun 3 Jun 19 – Jul 3
Beets – May 6 – 20 Jul 3 – 17
Kale Mar 25 – Apr 8 May 6 – 20 Jul 3 – 17
Broccoli Mar 25 – Apr 8 May 20 – Jun 3 Jul 3 – 17
Cabbage Mar 11 – 25 May 6 – 20 Jul 3 – 17
Garlic – – Jul 31 – Aug 21
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 3 –
Sweet corn Season usually too short. Try a quick variety or row covers.
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 3May 15
Fall frost before August 30September 11September 24

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 14 (June 2 in a late year), and the first one in fall around September 21.

Where these dates come from

NOAA weather station HAMER 4 NW, ID US (USC00103964), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 17 miles:

83425, 83444, 83450

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