Frost Report

All states Idaho

Frost dates for Lava Hot Springs, 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 21

typical year

Safe to plant

June 11

frost is over in 9 of 10 years

First fall frost

September 21

typical year

Growing season

118 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 23 – May 7 –
Spinach – Apr 9 – 30 Jul 27 – Aug 10
Lettuce – Apr 23 – May 14 Jul 27 – Aug 10
Radishes – Apr 23 – Jun 4 Aug 10 – 24
Onions – Apr 23 – May 7 –
Potatoes – Apr 30 – May 14 –
Carrots – Apr 30 – May 21 Jun 29 – Jul 13
Beets – Apr 23 – May 7 Jul 13 – 27
Kale Mar 12 – 26 Apr 23 – May 7 Jul 13 – 27
Broccoli Mar 12 – 26 May 7 – 21 Jul 13 – 27
Cabbage Feb 26 – Mar 12 Apr 23 – May 7 Jul 13 – 27
Garlic – – Aug 10 – 31
Warm-season crops
Tomatoes Apr 16 – 30 Jun 11 – 25 –
Peppers Apr 9 – 23 Jun 18 – Jul 2 –
Cucumbers – Jun 11 – Jul 2 –
Zucchini – Jun 11 – Jul 9 –
Pumpkins – Jun 11 – Jul 2 –
Green beans – Jun 11 – Jul 13 –
Sweet corn – Jun 11 – Jul 9 –
Basil May 7 – 21 Jun 18 – 25 –

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 11May 21May 6
Fall frost before September 3September 21October 6

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 3 (May 19 in a late year), and the first one in fall around October 5.

Towns that use these dates

This is the nearest NOAA station with frost records for 2 towns.

Lava Hot Springs, Bancroft

Where these dates come from

NOAA weather station LAVA HOT SPRINGS, ID US (USC00105143), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 11 miles:

83217, 83246

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