Frost Report

All states Arizona

Frost dates for Painted Rock Dam, 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

January 21

typical year

Safe to plant

February 18

frost is over in 9 of 10 years

First fall frost

December 15

typical year

Growing season

327 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 – Dec 24 – Jan 7 –
Spinach – Dec 10 – 31 Oct 20 – Nov 3
Lettuce – Dec 24 – Jan 14 Oct 20 – Nov 3
Radishes – Dec 24 – Feb 4 Nov 3 – 17
Onions – Dec 24 – Jan 7 –
Potatoes – Dec 31 – Jan 14 –
Carrots – Dec 31 – Jan 21 Sep 22 – Oct 6
Beets – Dec 24 – Jan 7 Oct 6 – 20
Kale Nov 12 – 26 Dec 24 – Jan 7 Oct 6 – 20
Broccoli Nov 12 – 26 Jan 7 – 21 Oct 6 – 20
Cabbage Oct 29 – Nov 12 Dec 24 – Jan 7 Oct 6 – 20
Garlic – – Nov 3 – 24
Warm-season crops
Tomatoes Dec 24 – Jan 7 Feb 18 – Mar 4 –
Peppers Dec 17 – 31 Feb 25 – Mar 11 –
Cucumbers – Feb 18 – Mar 11 –
Zucchini – Feb 18 – Mar 18 –
Pumpkins – Feb 18 – Mar 11 –
Green beans – Feb 18 – Oct 6 –
Sweet corn – Feb 18 – Mar 18 –
Basil Jan 14 – 28 Feb 25 – Mar 4 –

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 February 18January 21December 24
Fall frost before November 27December 15January 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 January 8 (February 6 in a late year), and the first one in fall around December 28.

Where these dates come from

NOAA weather station PAINTED ROCK DAM, AZ US (USC00026194), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 23 miles:

85322, 85354

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