Frost Report

All states Wyoming

Frost dates for Jackson, WY

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 20

typical year

Safe to plant

July 9

frost is over in 9 of 10 years

First fall frost

August 31

typical year

Growing season

70 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 Season usually too short. Try a quick variety or row covers.
Spinach – May 9 – 30 Jul 6 – 20
Lettuce – May 23 – Jun 13 Jul 6 – 20
Radishes – May 23 – Jul 4 Jul 20 – Aug 3
Onions – May 23 – Jun 6 –
Potatoes Season usually too short. Try a quick variety or row covers.
Carrots – May 30 – Jun 20 Jun 8 – 22
Beets – May 23 – Jun 6 Jun 22 – Jul 6
Kale Apr 11 – 25 May 23 – Jun 6 Jun 22 – Jul 6
Broccoli Apr 11 – 25 Jun 6 – 20 Jun 22 – Jul 6
Cabbage Mar 28 – Apr 11 May 23 – Jun 6 Jun 22 – Jul 6
Garlic – – Jul 20 – Aug 10
Warm-season crops
Tomatoes Season usually too short. Try a quick variety or row covers.
Peppers Season usually too short. Try a quick variety or row covers.
Cucumbers Season usually too short. Try a quick variety or row covers.
Zucchini Season usually too short. Try a quick variety or row covers.
Pumpkins Season usually too short. Try a quick variety or row covers.
Green beans Season usually too short. Try a quick variety or row covers.
Sweet corn Season usually too short. Try a quick variety or row covers.
Basil Season usually too short. Try a quick variety or row covers.

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 July 9June 20June 5
Fall frost before August 12August 31September 13

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 June 2 (June 21 in a late year), and the first one in fall around September 13.

Towns that use these dates

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

Jackson

Where these dates come from

NOAA weather station MOOSE, WY US (USC00486428), 1991–2020 climate normals. It's the nearest station for 4 zip codes, all within 19 miles:

83001, 83011, 83014, 83025

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