Frost Dates for Tucson, AZ
In Tucson, AZ, the average last spring frost is around Feb 5 and the average first fall frost around Dec 9, for a growing season of about 307 days. For frost-tender plants, wait until Mar 2, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Tucson Intl. Airport, AZ weather station, 5 miles away, elevation 2,549 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | Mar 2 | Nov 21 |
| 20% | Feb 23 | Nov 26 |
| 30% | Feb 17 | Nov 30 |
| 40% | Feb 11 | Dec 5 |
| 50% | Feb 5 | Dec 9 |
| 60% | Jan 31 | Dec 13 |
| 70% | Jan 23 | Dec 17 |
| 80% | Jan 14 | Dec 24 |
| 90% | Jan 4 | Jan 3 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | Feb 28 | Nov 26 |
| Frost / freeze (32°F) | Feb 5 | Dec 9 |
| Hard freeze (28°F) | Jan 11 | Dec 26 |
Planting calendar for Tucson
Transplant Feb 12 – Feb 26
Transplant Feb 19 – Mar 5
Transplant Feb 19 – Mar 5
Transplant Feb 12 – Feb 26
Sow or transplant Feb 12 – Feb 26
Sow or transplant Feb 12 – Feb 26
Sow or transplant Feb 19 – Mar 5
Sow or transplant Jan 8 – Jan 22
Fall sowing Oct 14 – Nov 11
Fall sowing Oct 14 – Nov 4
Fall sowing Sep 30 – Oct 14
Sow or transplant Jan 8 – Jan 22
Fall sowing Sep 30 – Oct 28
Transplant Jan 22 – Feb 5
Fall sowing Sep 16 – Sep 30
Transplant Jan 15 – Jan 29
Fall sowing Sep 16 – Sep 30
Fall sowing Sep 16 – Sep 30
Fall sowing Oct 28 – Nov 18
Fall sowing Sep 30 – Oct 14
Plant Jan 8 – Jan 22
Based on the average last frost (Feb 5) and first frost (Dec 9). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.