Frost Report

All states Washington

Frost dates for Ellensburg, WA

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 8

typical year

Safe to plant

May 25

frost is over in 9 of 10 years

First fall frost

October 2

typical year

Growing season

146 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 10 – 24 –
Spinach – Mar 27 – Apr 17 Aug 7 – 21
Lettuce – Apr 10 – May 1 Aug 7 – 21
Radishes – Apr 10 – May 22 Aug 21 – Sep 4
Onions – Apr 10 – 24 –
Potatoes – Apr 17 – May 1 –
Carrots – Apr 17 – May 8 Jul 10 – 24
Beets – Apr 10 – 24 Jul 24 – Aug 7
Kale Feb 27 – Mar 13 Apr 10 – 24 Jul 24 – Aug 7
Broccoli Feb 27 – Mar 13 Apr 24 – May 8 Jul 24 – Aug 7
Cabbage Feb 13 – 27 Apr 10 – 24 Jul 24 – Aug 7
Garlic – – Aug 21 – Sep 11
Warm-season crops
Tomatoes Mar 30 – Apr 13 May 25 – Jun 8 –
Peppers Mar 23 – Apr 6 Jun 1 – 15 –
Cucumbers – May 25 – Jun 15 –
Zucchini – May 25 – Jun 22 –
Pumpkins – May 25 – Jun 15 –
Green beans – May 25 – Jul 24 –
Sweet corn – May 25 – Jun 22 –
Basil Apr 20 – May 4 Jun 1 – 8 –

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 May 25May 8April 25
Fall frost before September 20October 2October 14

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 April 23 (May 6 in a late year), and the first one in fall around October 14.

Towns that use these dates

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

Ellensburg, Kittitas

Where these dates come from

NOAA weather station ELLENSBURG, WA US (USC00452505), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 9 miles:

98926, 98934

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