Frost Report

All states Arizona

Frost dates for Willcox, AZ

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

April 9

typical year

Safe to plant

April 29

frost is over in 9 of 10 years

First fall frost

October 31

typical year

Growing season

204 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 – Mar 12 – 26 –
Spinach – Feb 26 – Mar 19 Sep 5 – 19
Lettuce – Mar 12 – Apr 2 Sep 5 – 19
Radishes – Mar 12 – Apr 23 Sep 19 – Oct 3
Onions – Mar 12 – 26 –
Potatoes – Mar 19 – Apr 2 –
Carrots – Mar 19 – Apr 9 Aug 8 – 22
Beets – Mar 12 – 26 Aug 22 – Sep 5
Kale Jan 29 – Feb 12 Mar 12 – 26 Aug 22 – Sep 5
Broccoli Jan 29 – Feb 12 Mar 26 – Apr 9 Aug 22 – Sep 5
Cabbage Jan 15 – 29 Mar 12 – 26 Aug 22 – Sep 5
Garlic – – Sep 19 – Oct 10
Warm-season crops
Tomatoes Mar 4 – 18 Apr 29 – May 13 –
Peppers Feb 25 – Mar 11 May 6 – 20 –
Cucumbers – Apr 29 – May 20 –
Zucchini – Apr 29 – May 27 –
Pumpkins – Apr 29 – May 20 –
Green beans – Apr 29 – Aug 22 –
Sweet corn – Apr 29 – May 27 –
Basil Mar 25 – Apr 8 May 6 – 13 –

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 April 29April 9March 20
Fall frost before October 20October 31November 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 March 16 (April 10 in a late year), and the first one in fall around November 12.

Towns that use these dates

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

Willcox

Where these dates come from

NOAA weather station WILLCOX, AZ US (USC00029334), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 15 miles:

85643

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