Frost dates for 85644Willcox, AZ
The average last spring frost in Willcox is April 9 and the average first fall frost is October 31, giving a typical growing season of about 204 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 9
- Average first fall frost
- Oct 31
- Growing season
- 204 days
Safer after Apr 29 (1-in-10 risk)
Possible by Oct 20 (1-in-10 risk)
First frost typically in 4 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 9 · Apr 26 · May 10 | Oct 11 · Oct 22 · Nov 3 | 178 days | 100% |
| Frost / freeze (32°F) | Mar 20 · Apr 9 · Apr 29 | Oct 20 · Oct 31 · Nov 14 | 204 days | 100% |
| Hard freeze (28°F) | Feb 24 · Mar 16 · Apr 10 | Oct 28 · Nov 12 · Nov 26 | 237 days | 100% |
Planting calendar for Willcox
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 9 – May 15 |
| Tomatoes | Transplant outdoors | Apr 25 – Jul 11 |
| Peppers | Start seeds indoors | Mar 9 – Apr 9 |
| Peppers | Transplant outdoors | May 9 – Jun 9 |
| Eggplant | Start seeds indoors | Mar 26 – Apr 24 |
| Eggplant | Transplant outdoors | May 9 – Jun 9 |
| Cucumbers | Sow outdoors | May 9 – Jul 21 |
| Summer squash | Sow outdoors | Apr 25 – Jun 9 |
| Winter squash & pumpkins | Sow outdoors | May 9 – Jun 9 |
| Snap beans | Sow outdoors | Apr 25 – Aug 13 |
| Sweet corn | Sow outdoors | Apr 25 – Jul 11 |
| Watermelon & cantaloupe | Sow outdoors | May 9 – Jun 9 |
| Okra | Sow outdoors | May 2 – May 25 |
| Peas | Sow outdoors (spring) | Mar 9 – Apr 24 |
| Potatoes | Plant outdoors (spring) | Mar 9 – May 9 |
| Onions | Start seeds indoors (spring) | Jan 26 – Feb 22 |
| Onions | Transplant outdoors (spring) | Mar 26 – Apr 24 |
| Broccoli | Start seeds indoors (spring) | Feb 19 – Mar 25 |
| Broccoli | Transplant outdoors (spring) | Mar 26 – Apr 24 |
| Broccoli | Start seeds indoors (fall) | Jul 1 – Jul 11 |
| Broccoli | Transplant outdoors (fall) | Jul 31 – Aug 11 |
| Cabbage | Start seeds indoors (spring) | Feb 9 – Mar 9 |
| Cabbage | Transplant outdoors (spring) | Mar 9 – Apr 9 |
| Cabbage | Start seeds indoors (fall) | Jun 21 – Jul 21 |
| Cabbage | Transplant outdoors (fall) | Jul 21 – Aug 21 |
| Leaf lettuce | Sow outdoors (spring) | Mar 9 – May 25 |
| Leaf lettuce | Sow outdoors (fall) | Jul 21 – Sep 6 |
| Spinach | Sow outdoors (spring) | Mar 2 – Apr 15 |
| Spinach | Sow outdoors (fall) | Aug 7 – Sep 11 |
| Radishes | Sow outdoors (spring) | Mar 9 – Apr 29 |
| Radishes | Sow outdoors (fall) | Jul 21 – Sep 21 |
| Kale | Sow outdoors (spring) | Mar 26 – Apr 15 |
| Kale | Sow outdoors (fall) | Jul 14 – Aug 21 |
| Carrots | Sow outdoors (spring) | Apr 9 – May 25 |
| Carrots | Sow outdoors (fall) | Jun 21 – Aug 6 |
| Garlic | Plant outdoors (fall) | Oct 21 – Nov 21 |
Where these dates come from
ZIP code 85644 is matched to the NOAA station Willcox, AZ, 0.5 km away, at 4,170 ft elevation (0 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Willcox, AZ (used) | 4,170 ft | Apr 9 | Oct 31 |
| Bowie, AZ | 3,777 ft | Apr 1 | Nov 6 |
| Pearce - Sunsites, AZ | 4,350 ft | Apr 14 | Nov 2 |
| Cascabel, AZ | 3,194 ft | Apr 24 | Oct 31 |
Frost dates near Willcox
- Willcox, AZ 85643 · last Apr 9, first Oct 31
- Cochise, AZ 85606 · last Apr 9, first Oct 31
- Dragoon, AZ 85609 · last Apr 14, first Nov 2
- Bowie, AZ 85605 · last Apr 1, first Nov 6
- Fort Huachuca, AZ 85670 · last Apr 14, first Nov 2
- Pearce, AZ 85625 · last Apr 14, first Nov 2
- Pomerene, AZ 85627 · last Apr 12, first Nov 1
- Benson, AZ 85602 · last Apr 12, first Nov 1
Frequently asked questions
- When is the last frost in Willcox, AZ?
- For ZIP code 85644, the average last spring frost (32°F) is April 9, based on NOAA 1991-2020 climate normals for the Willcox, AZ weather station. There is a 1-in-10 chance of a frost after April 29.
- When is the first frost in Willcox, AZ?
- The average first fall frost (32°F) is October 31. There is a 1-in-10 chance of frost by October 20, so tender plants are at risk from that point on.
- How long is the growing season in 85644?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 204 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.