Frost dates for 85540Morenci, AZ
The average last spring frost in Morenci is May 6 and the average first fall frost is October 18, giving a typical growing season of about 164 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 6
- Average first fall frost
- Oct 18
- Growing season
- 164 days
Safer after May 20 (1-in-10 risk)
Possible by Oct 7 (1-in-10 risk)
Last frost typically in 186 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) | May 5 · May 21 · Jun 5 | Sep 27 · Oct 9 · Oct 20 | 138 days | 100% |
| Frost / freeze (32°F) | Apr 21 · May 6 · May 20 | Oct 7 · Oct 18 · Oct 30 | 164 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 21 · May 7 | Oct 13 · Oct 28 · Nov 10 | 188 days | 100% |
Planting calendar for Morenci
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 | Apr 5 – Jun 11 |
| Tomatoes | Transplant outdoors | May 22 – Jun 28 |
| Peppers | Start seeds indoors | Apr 5 – May 6 |
| Peppers | Transplant outdoors | Jun 5 – Jul 6 |
| Eggplant | Start seeds indoors | Apr 22 – May 21 |
| Eggplant | Transplant outdoors | Jun 5 – Jul 6 |
| Cucumbers | Sow outdoors | Jun 5 – Jul 8 |
| Summer squash | Sow outdoors | May 22 – Jul 6 |
| Winter squash & pumpkins | Sow outdoors | Jun 5 – Jul 6 |
| Snap beans | Sow outdoors | May 22 – Jul 31 |
| Sweet corn | Sow outdoors | May 22 – Jun 28 |
| Watermelon & cantaloupe | Sow outdoors | Jun 5 – Jul 6 |
| Okra | Sow outdoors | May 29 – Jun 21 |
| Peas | Sow outdoors (spring) | Apr 5 – May 21 |
| Potatoes | Plant outdoors (spring) | Apr 5 – Jun 5 |
| Onions | Start seeds indoors (spring) | Feb 22 – Mar 21 |
| Onions | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (spring) | Mar 18 – Apr 21 |
| Broccoli | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (fall) | Jun 18 – Jun 28 |
| Broccoli | Transplant outdoors (fall) | Jul 18 – Jul 29 |
| Cabbage | Start seeds indoors (spring) | Mar 8 – Apr 5 |
| Cabbage | Transplant outdoors (spring) | Apr 5 – May 6 |
| Cabbage | Start seeds indoors (fall) | Jun 8 – Jul 8 |
| Cabbage | Transplant outdoors (fall) | Jul 8 – Aug 8 |
| Leaf lettuce | Sow outdoors (spring) | Apr 5 – Jun 21 |
| Leaf lettuce | Sow outdoors (fall) | Jul 8 – Aug 24 |
| Spinach | Sow outdoors (spring) | Mar 29 – May 12 |
| Spinach | Sow outdoors (fall) | Jul 25 – Aug 29 |
| Radishes | Sow outdoors (spring) | Apr 5 – May 26 |
| Radishes | Sow outdoors (fall) | Jul 8 – Sep 8 |
| Kale | Sow outdoors (spring) | Apr 22 – May 12 |
| Kale | Sow outdoors (fall) | Jul 1 – Aug 8 |
| Carrots | Sow outdoors (spring) | May 6 – Jun 21 |
| Carrots | Sow outdoors (fall) | Jun 8 – Jul 24 |
| Garlic | Plant outdoors (fall) | Oct 8 – Nov 8 |
Where these dates come from
ZIP code 85540 is matched to the NOAA station Glenwood, NM, 52.7 km away, at 4,725 ft elevation (344 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Glenwood, NM (used) | 4,725 ft | May 6 | Oct 18 |
| Clifton, AZ | 3,520 ft | Feb 26 | Nov 23 |
| Safford Muni Ap, AZ | 3,176 ft | Mar 8 | Nov 20 |
| Safford Ag Ctr, AZ | 2,954 ft | Mar 25 | Nov 9 |
Frost dates near Morenci
- Clifton, AZ 85533 · last May 6, first Oct 18
- Duncan, AZ 85534 · last Apr 24, first Oct 25
- Safford, AZ 85546 · last Mar 25, first Nov 9
- Solomon, AZ 85551 · last Mar 25, first Nov 9
- Mule Creek, NM 88051 · last May 26, first Oct 5
- Thatcher, AZ 85552 · last Mar 25, first Nov 9
- Central, AZ 85531 · last Mar 25, first Nov 9
- Pima, AZ 85543 · last Apr 1, first Nov 6
Frequently asked questions
- When is the last frost in Morenci, AZ?
- For ZIP code 85540, the average last spring frost (32°F) is May 6, based on NOAA 1991-2020 climate normals for the Glenwood, NM weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Morenci, AZ?
- The average first fall frost (32°F) is October 18. There is a 1-in-10 chance of frost by October 7, so tender plants are at risk from that point on.
- How long is the growing season in 85540?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 164 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.