Frost Report

All states Washington

Frost dates for Plain, 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 22

typical year

Safe to plant

June 13

frost is over in 9 of 10 years

First fall frost

September 22

typical year

Growing season

121 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 24 – May 8 –
Spinach – Apr 10 – May 1 Jul 28 – Aug 11
Lettuce – Apr 24 – May 15 Jul 28 – Aug 11
Radishes – Apr 24 – Jun 5 Aug 11 – 25
Onions – Apr 24 – May 8 –
Potatoes – May 1 – 15 –
Carrots – May 1 – 22 Jun 30 – Jul 14
Beets – Apr 24 – May 8 Jul 14 – 28
Kale Mar 13 – 27 Apr 24 – May 8 Jul 14 – 28
Broccoli Mar 13 – 27 May 8 – 22 Jul 14 – 28
Cabbage Feb 27 – Mar 13 Apr 24 – May 8 Jul 14 – 28
Garlic – – Aug 11 – Sep 1
Warm-season crops
Tomatoes Apr 18 – May 2 Jun 13 – 27 –
Peppers Apr 11 – 25 Jun 20 – Jul 4 –
Cucumbers – Jun 13 – Jul 4 –
Zucchini – Jun 13 – Jul 11 –
Pumpkins – Jun 13 – Jul 4 –
Green beans – Jun 13 – Jul 14 –
Sweet corn – Jun 13 – Jul 11 –
Basil May 9 – 23 Jun 20 – 27 –

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 13May 22May 2
Fall frost before September 7September 22October 4

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 20 in a late year), and the first one in fall around October 4.

Where these dates come from

NOAA weather station PLAIN, WA US (USC00456534), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 14 miles:

98822, 98826

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