Frost dates for Phoenix, 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 8
typical year
Safe to plant
February 12
frost is over in 9 of 10 years
First fall frost
December 25
typical year
Growing season
354 days
frost-free, typical year
Frost watch this week
Tonight's and the next six nights' lows from the National Weather Service forecast for the station's location. Frost: 32°F or colder. Possible frost: 33–36°F, mostly in low spots on clear, still nights.
When to plant
Counted from this page's frost dates. Warm-season crops wait for the safe-to-plant date.
| Crop | Start indoors | Plant outside | Fall planting |
|---|---|---|---|
| Cool-season crops | |||
| Peas | – | Dec 11 – 25 | – |
| Spinach | – | Nov 27 – Dec 18 | Oct 30 – Nov 13 |
| Lettuce | – | Dec 11 – Jan 1 | Oct 30 – Nov 13 |
| Radishes | – | Dec 11 – Jan 22 | Nov 13 – 27 |
| Onions | – | Dec 11 – 25 | – |
| Potatoes | – | Dec 18 – Jan 1 | – |
| Carrots | – | Dec 18 – Jan 8 | Oct 2 – 16 |
| Beets | – | Dec 11 – 25 | Oct 16 – 30 |
| Kale | Oct 30 – Nov 13 | Dec 11 – 25 | Oct 16 – 30 |
| Broccoli | Oct 30 – Nov 13 | Dec 25 – Jan 8 | Oct 16 – 30 |
| Cabbage | Oct 16 – 30 | Dec 11 – 25 | Oct 16 – 30 |
| Garlic | – | – | Nov 13 – Dec 4 |
| Warm-season crops | |||
| Tomatoes | Dec 18 – Jan 1 | Feb 12 – 26 | – |
| Peppers | Dec 11 – 25 | Feb 19 – Mar 5 | – |
| Cucumbers | – | Feb 12 – Mar 5 | – |
| Zucchini | – | Feb 12 – Mar 12 | – |
| Pumpkins | – | Feb 12 – Mar 5 | – |
| Green beans | – | Feb 12 – Oct 16 | – |
| Sweet corn | – | Feb 12 – Mar 12 | – |
| Basil | Jan 8 – 22 | Feb 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 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | February 12 | January 8 | December 16 |
| Fall frost before | December 5 | December 25 | January 23 |
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 2 in a late year), and the first one in fall around January 7.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
Phoenix
Where these dates come from
NOAA weather station PHOENIX DEER VALLEY MUNI AP, AZ US (USW00003184), 1991–2020 climate normals. It's the nearest station for 16 zip codes, all within 10 miles:
85020, 85021, 85022, 85023, 85024, 85027, 85029, 85050, 85051, 85053, 85083, 85085, 85086, 85306, 85308, 85310
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.