Frost Report

All states Arizona

Frost dates for Williams, 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

May 22

typical year

Safe to plant

June 10

frost is over in 9 of 10 years

First fall frost

October 5

typical year

Growing season

135 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 Aug 10 – 24
Lettuce – Apr 24 – May 15 Aug 10 – 24
Radishes – Apr 24 – Jun 5 Aug 24 – Sep 7
Onions – Apr 24 – May 8 –
Potatoes – May 1 – 15 –
Carrots – May 1 – 22 Jul 13 – 27
Beets – Apr 24 – May 8 Jul 27 – Aug 10
Kale Mar 13 – 27 Apr 24 – May 8 Jul 27 – Aug 10
Broccoli Mar 13 – 27 May 8 – 22 Jul 27 – Aug 10
Cabbage Feb 27 – Mar 13 Apr 24 – May 8 Jul 27 – Aug 10
Garlic – – Aug 24 – Sep 14
Warm-season crops
Tomatoes Apr 15 – 29 Jun 10 – 24 –
Peppers Apr 8 – 22 Jun 17 – Jul 1 –
Cucumbers – Jun 10 – Jul 1 –
Zucchini – Jun 10 – Jul 8 –
Pumpkins – Jun 10 – Jul 1 –
Green beans – Jun 10 – Jul 27 –
Sweet corn – Jun 10 – Jul 8 –
Basil May 6 – 20 Jun 17 – 24 –

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 10May 22May 6
Fall frost before September 24October 5October 18

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 9 (June 1 in a late year), and the first one in fall around October 15.

Towns that use these dates

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

Williams

Where these dates come from

NOAA weather station WILLIAMS, AZ US (USC00029359), 1991–2020 climate normals. It's the nearest station for 1 zip code, all within 14 miles:

86046

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