Frost Dates for Surprise, AZ
In Surprise, AZ, the average last spring frost is around Feb 5 and the average first fall frost around Dec 11, for a growing season of about 306 days. For frost-tender plants, wait until Mar 3, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Wittmann 1Se, AZ weather station, 8 miles away, elevation 1,683 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 3 | Nov 20 |
| 20% | Feb 24 | Nov 26 |
| 30% | Feb 16 | Dec 2 |
| 40% | Feb 11 | Dec 7 |
| 50% | Feb 5 | Dec 11 |
| 60% | Jan 31 | Dec 15 |
| 70% | Jan 24 | Dec 19 |
| 80% | Jan 16 | Dec 25 |
| 90% | Jan 6 | Jan 2 |
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) | Mar 4 | Nov 26 |
| Frost / freeze (32°F) | Feb 5 | Dec 11 |
| Hard freeze (28°F) | Jan 15 | Dec 27 |
Planting calendar for Surprise
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 16 – Nov 13
Fall sowing Oct 16 – Nov 6
Fall sowing Oct 2 – Oct 16
Sow or transplant Jan 8 – Jan 22
Fall sowing Oct 2 – Oct 30
Transplant Jan 22 – Feb 5
Fall sowing Sep 18 – Oct 2
Transplant Jan 15 – Jan 29
Fall sowing Sep 18 – Oct 2
Fall sowing Sep 18 – Oct 2
Fall sowing Oct 30 – Nov 20
Fall sowing Oct 2 – Oct 16
Plant Jan 8 – Jan 22
Based on the average last frost (Feb 5) and first frost (Dec 11). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.