Frost Report

All states Washington

Frost dates for Mt Adams Rs, 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 18

typical year

Safe to plant

June 12

frost is over in 9 of 10 years

First fall frost

September 25

typical year

Growing season

125 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 20 – May 4 –
Spinach – Apr 6 – 27 Jul 31 – Aug 14
Lettuce – Apr 20 – May 11 Jul 31 – Aug 14
Radishes – Apr 20 – Jun 1 Aug 14 – 28
Onions – Apr 20 – May 4 –
Potatoes – Apr 27 – May 11 –
Carrots – Apr 27 – May 18 Jul 3 – 17
Beets – Apr 20 – May 4 Jul 17 – 31
Kale Mar 9 – 23 Apr 20 – May 4 Jul 17 – 31
Broccoli Mar 9 – 23 May 4 – 18 Jul 17 – 31
Cabbage Feb 23 – Mar 9 Apr 20 – May 4 Jul 17 – 31
Garlic – – Aug 14 – Sep 4
Warm-season crops
Tomatoes Apr 17 – May 1 Jun 12 – 26 –
Peppers Apr 10 – 24 Jun 19 – Jul 3 –
Cucumbers – Jun 12 – Jul 3 –
Zucchini – Jun 12 – Jul 10 –
Pumpkins – Jun 12 – Jul 3 –
Green beans – Jun 12 – Jul 17 –
Sweet corn – Jun 12 – Jul 10 –
Basil May 8 – 22 Jun 19 – 26 –

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 12May 18May 1
Fall frost before September 4September 25October 10

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 29 (May 16 in a late year), and the first one in fall around October 9.

Where these dates come from

NOAA weather station MT ADAMS RS, WA US (USC00455659), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 4 miles:

98650

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