Frost dates for South Tucson, 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 20
typical year
Safe to plant
February 18
frost is over in 9 of 10 years
First fall frost
December 17
typical year
Growing season
332 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 23 – Jan 6 | – |
| Spinach | – | Dec 9 – 30 | Oct 22 – Nov 5 |
| Lettuce | – | Dec 23 – Jan 13 | Oct 22 – Nov 5 |
| Radishes | – | Dec 23 – Feb 3 | Nov 5 – 19 |
| Onions | – | Dec 23 – Jan 6 | – |
| Potatoes | – | Dec 30 – Jan 13 | – |
| Carrots | – | Dec 30 – Jan 20 | Sep 24 – Oct 8 |
| Beets | – | Dec 23 – Jan 6 | Oct 8 – 22 |
| Kale | Nov 11 – 25 | Dec 23 – Jan 6 | Oct 8 – 22 |
| Broccoli | Nov 11 – 25 | Jan 6 – 20 | Oct 8 – 22 |
| Cabbage | Oct 28 – Nov 11 | Dec 23 – Jan 6 | Oct 8 – 22 |
| Garlic | – | – | Nov 5 – 26 |
| 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 8 | – |
| 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 10 | Half of years | 9 years in 10 | |
|---|---|---|---|
| Spring frost after | February 18 | January 20 | December 19 |
| Fall frost before | November 28 | December 17 | January 12 |
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 4 (February 7 in a late year), and the first one in fall around December 30.
Towns that use these dates
This is the nearest NOAA station with frost records for 1 town.
South Tucson
Where these dates come from
NOAA weather station TUCSON WFO, AZ US (USC00028815), 1991–2020 climate normals. It's the nearest station for 10 zip codes, all within 5 miles:
85701, 85707, 85711, 85713, 85716, 85719, 85721, 85723, 85724, 85726
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.