Frost dates for 85552Thatcher, AZ
The average last spring frost in Thatcher is March 25 and the average first fall frost is November 9, giving a typical growing season of about 228 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 25
- Average first fall frost
- Nov 9
- Growing season
- 228 days
Safer after Apr 14 (1-in-10 risk)
Possible by Oct 23 (1-in-10 risk)
First frost typically in 13 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) | Mar 25 · Apr 12 · May 2 | Oct 14 · Oct 30 · Nov 13 | 197 days | 100% |
| Frost / freeze (32°F) | Mar 5 · Mar 25 · Apr 14 | Oct 23 · Nov 9 · Nov 25 | 228 days | 100% |
| Hard freeze (28°F) | Feb 8 · Mar 3 · Mar 23 | Nov 3 · Nov 22 · Dec 6 | 260 days | 100% |
Planting calendar for Thatcher
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 | Feb 22 – Apr 30 |
| Tomatoes | Transplant outdoors | Apr 10 – Jul 20 |
| Peppers | Start seeds indoors | Feb 22 – Mar 25 |
| Peppers | Transplant outdoors | Apr 24 – May 25 |
| Eggplant | Start seeds indoors | Mar 11 – Apr 9 |
| Eggplant | Transplant outdoors | Apr 24 – May 25 |
| Cucumbers | Sow outdoors | Apr 24 – Jul 30 |
| Summer squash | Sow outdoors | Apr 10 – May 25 |
| Winter squash & pumpkins | Sow outdoors | Apr 24 – May 25 |
| Snap beans | Sow outdoors | Apr 10 – Aug 22 |
| Sweet corn | Sow outdoors | Apr 10 – Jul 20 |
| Watermelon & cantaloupe | Sow outdoors | Apr 24 – May 25 |
| Okra | Sow outdoors | Apr 17 – May 10 |
| Peas | Sow outdoors (spring) | Feb 22 – Apr 9 |
| Potatoes | Plant outdoors (spring) | Feb 22 – Apr 24 |
| Onions | Start seeds indoors (spring) | Jan 11 – Feb 7 |
| Onions | Transplant outdoors (spring) | Mar 11 – Apr 9 |
| Broccoli | Start seeds indoors (spring) | Feb 4 – Mar 10 |
| Broccoli | Transplant outdoors (spring) | Mar 11 – Apr 9 |
| Broccoli | Start seeds indoors (fall) | Jul 10 – Jul 20 |
| Broccoli | Transplant outdoors (fall) | Aug 9 – Aug 20 |
| Cabbage | Start seeds indoors (spring) | Jan 25 – Feb 22 |
| Cabbage | Transplant outdoors (spring) | Feb 22 – Mar 25 |
| Cabbage | Start seeds indoors (fall) | Jun 30 – Jul 30 |
| Cabbage | Transplant outdoors (fall) | Jul 30 – Aug 30 |
| Leaf lettuce | Sow outdoors (spring) | Feb 22 – May 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 30 – Sep 15 |
| Spinach | Sow outdoors (spring) | Feb 15 – Mar 31 |
| Spinach | Sow outdoors (fall) | Aug 16 – Sep 20 |
| Radishes | Sow outdoors (spring) | Feb 22 – Apr 14 |
| Radishes | Sow outdoors (fall) | Jul 30 – Sep 30 |
| Kale | Sow outdoors (spring) | Mar 11 – Mar 31 |
| Kale | Sow outdoors (fall) | Jul 23 – Aug 30 |
| Carrots | Sow outdoors (spring) | Mar 25 – May 10 |
| Carrots | Sow outdoors (fall) | Jun 30 – Aug 15 |
| Garlic | Plant outdoors (fall) | Oct 30 – Nov 30 |
Where these dates come from
ZIP code 85552 is matched to the NOAA station Safford Ag Ctr, AZ, 7.3 km away, at 2,954 ft elevation (54 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Safford Ag Ctr, AZ (used) | 2,954 ft | Mar 25 | Nov 9 |
| Safford Muni Ap, AZ | 3,176 ft | Mar 8 | Nov 20 |
| Ft Thomas 2 Sw, AZ | 2,835 ft | Apr 1 | Nov 6 |
| Clifton, AZ | 3,520 ft | Feb 26 | Nov 23 |
Frost dates near Thatcher
- Central, AZ 85531 · last Mar 25, first Nov 9
- Safford, AZ 85548 · last Mar 25, first Nov 9
- Solomon, AZ 85551 · last Mar 25, first Nov 9
- Pima, AZ 85543 · last Apr 1, first Nov 6
- Eden, AZ 85535 · last Apr 1, first Nov 6
- Fort Thomas, AZ 85536 · last Apr 1, first Nov 6
- Morenci, AZ 85540 · last May 6, first Oct 18
- Bylas, AZ 85530 · last Apr 1, first Nov 6
Frequently asked questions
- When is the last frost in Thatcher, AZ?
- For ZIP code 85552, the average last spring frost (32°F) is March 25, based on NOAA 1991-2020 climate normals for the Safford Ag Ctr, AZ weather station. There is a 1-in-10 chance of a frost after April 14.
- When is the first frost in Thatcher, AZ?
- The average first fall frost (32°F) is November 9. There is a 1-in-10 chance of frost by October 23, so tender plants are at risk from that point on.
- How long is the growing season in 85552?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 228 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.