Frost dates for Superior, 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 18
typical year
Safe to plant
March 1
frost is over in 9 of 10 years
First fall frost
December 28
typical year
Growing season
342 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 21 – Jan 4 | – |
| Spinach | – | Dec 7 – 28 | Nov 2 – 16 |
| Lettuce | – | Dec 21 – Jan 11 | Nov 2 – 16 |
| Radishes | – | Dec 21 – Feb 1 | Nov 16 – 30 |
| Onions | – | Dec 21 – Jan 4 | – |
| Potatoes | – | Dec 28 – Jan 11 | – |
| Carrots | – | Dec 28 – Jan 18 | Oct 5 – 19 |
| Beets | – | Dec 21 – Jan 4 | Oct 19 – Nov 2 |
| Kale | Nov 9 – 23 | Dec 21 – Jan 4 | Oct 19 – Nov 2 |
| Broccoli | Nov 9 – 23 | Jan 4 – 18 | Oct 19 – Nov 2 |
| Cabbage | Oct 26 – Nov 9 | Dec 21 – Jan 4 | Oct 19 – Nov 2 |
| Garlic | – | – | Nov 16 – Dec 7 |
| Warm-season crops | |||
| Tomatoes | Jan 4 – 18 | Mar 1 – 15 | – |
| Peppers | Dec 28 – Jan 11 | Mar 8 – 22 | – |
| Cucumbers | – | Mar 1 – 22 | – |
| Zucchini | – | Mar 1 – 29 | – |
| Pumpkins | – | Mar 1 – 22 | – |
| Green beans | – | Mar 1 – Oct 19 | – |
| Sweet corn | – | Mar 1 – 29 | – |
| Basil | Jan 25 – Feb 8 | Mar 8 – 15 | – |
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 | March 1 | January 18 | December 19 |
| Fall frost before | December 1 | December 28 | February 1 |
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 9 (February 10 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 2 towns.
Superior, Kearny
Where these dates come from
NOAA weather station SUPERIOR, AZ US (USC00028348), 1991–2020 climate normals. It's the nearest station for 2 zip codes, all within 12 miles:
85137, 85173
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.