Frost dates for 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
February 23
typical year
Safe to plant
March 22
frost is over in 9 of 10 years
First fall frost
December 6
typical year
Growing season
287 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 | – | Jan 26 – Feb 9 | – |
| Spinach | – | Jan 12 – Feb 2 | Oct 11 – 25 |
| Lettuce | – | Jan 26 – Feb 16 | Oct 11 – 25 |
| Radishes | – | Jan 26 – Mar 9 | Oct 25 – Nov 8 |
| Onions | – | Jan 26 – Feb 9 | – |
| Potatoes | – | Feb 2 – 16 | – |
| Carrots | – | Feb 2 – 23 | Sep 13 – 27 |
| Beets | – | Jan 26 – Feb 9 | Sep 27 – Oct 11 |
| Kale | Dec 15 – 29 | Jan 26 – Feb 9 | Sep 27 – Oct 11 |
| Broccoli | Dec 15 – 29 | Feb 9 – 23 | Sep 27 – Oct 11 |
| Cabbage | Dec 1 – 15 | Jan 26 – Feb 9 | Sep 27 – Oct 11 |
| Garlic | – | – | Oct 25 – Nov 15 |
| Warm-season crops | |||
| Tomatoes | Jan 25 – Feb 8 | Mar 22 – Apr 5 | – |
| Peppers | Jan 18 – Feb 1 | Mar 29 – Apr 12 | – |
| Cucumbers | – | Mar 22 – Apr 12 | – |
| Zucchini | – | Mar 22 – Apr 19 | – |
| Pumpkins | – | Mar 22 – Apr 12 | – |
| Green beans | – | Mar 22 – Sep 27 | – |
| Sweet corn | – | Mar 22 – Apr 19 | – |
| Basil | Feb 15 – Mar 1 | Mar 29 – Apr 5 | – |
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 22 | February 23 | January 15 |
| Fall frost before | November 18 | December 6 | December 25 |
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 22 (March 1 in a late year), and the first one in fall around December 19.
Where these dates come from
NOAA weather station TUCSON 17 NW, AZ US (USC00028795), 1991–2020 climate normals. It's the nearest station for 3 zip codes, all within 15 miles:
85653, 85654, 85743
Planting dates follow common university extension advice; your local extension service can fine-tune them for your soil and microclimate.