Frost dates for 85620Naco, AZ
The average last spring frost in Naco is April 5 and the average first fall frost is November 9, giving a typical growing season of about 216 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 5
- Average first fall frost
- Nov 9
- Growing season
- 216 days
Safer after Apr 21 (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) | Apr 5 · Apr 20 · May 4 | Oct 15 · Oct 30 · Nov 12 | 191 days | 100% |
| Frost / freeze (32°F) | Mar 15 · Apr 5 · Apr 21 | Oct 23 · Nov 9 · Nov 23 | 216 days | 100% |
| Hard freeze (28°F) | Feb 21 · Mar 15 · Apr 5 | Nov 4 · Nov 21 · Dec 5 | 248 days | 100% |
Planting calendar for Naco
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 5 – May 11 |
| Tomatoes | Transplant outdoors | Apr 21 – Jul 20 |
| Peppers | Start seeds indoors | Mar 5 – Apr 5 |
| Peppers | Transplant outdoors | May 5 – Jun 5 |
| Eggplant | Start seeds indoors | Mar 22 – Apr 20 |
| Eggplant | Transplant outdoors | May 5 – Jun 5 |
| Cucumbers | Sow outdoors | May 5 – Jul 30 |
| Summer squash | Sow outdoors | Apr 21 – Jun 5 |
| Winter squash & pumpkins | Sow outdoors | May 5 – Jun 5 |
| Snap beans | Sow outdoors | Apr 21 – Aug 22 |
| Sweet corn | Sow outdoors | Apr 21 – Jul 20 |
| Watermelon & cantaloupe | Sow outdoors | May 5 – Jun 5 |
| Okra | Sow outdoors | Apr 28 – May 21 |
| Peas | Sow outdoors (spring) | Mar 5 – Apr 20 |
| Potatoes | Plant outdoors (spring) | Mar 5 – May 5 |
| Onions | Start seeds indoors (spring) | Jan 22 – Feb 18 |
| Onions | Transplant outdoors (spring) | Mar 22 – Apr 20 |
| Broccoli | Start seeds indoors (spring) | Feb 15 – Mar 21 |
| Broccoli | Transplant outdoors (spring) | Mar 22 – Apr 20 |
| Broccoli | Start seeds indoors (fall) | Jul 10 – Jul 20 |
| Broccoli | Transplant outdoors (fall) | Aug 9 – Aug 20 |
| Cabbage | Start seeds indoors (spring) | Feb 5 – Mar 5 |
| Cabbage | Transplant outdoors (spring) | Mar 5 – Apr 5 |
| Cabbage | Start seeds indoors (fall) | Jun 30 – Jul 30 |
| Cabbage | Transplant outdoors (fall) | Jul 30 – Aug 30 |
| Leaf lettuce | Sow outdoors (spring) | Mar 5 – May 21 |
| Leaf lettuce | Sow outdoors (fall) | Jul 30 – Sep 15 |
| Spinach | Sow outdoors (spring) | Feb 26 – Apr 11 |
| Spinach | Sow outdoors (fall) | Aug 16 – Sep 20 |
| Radishes | Sow outdoors (spring) | Mar 5 – Apr 25 |
| Radishes | Sow outdoors (fall) | Jul 30 – Sep 30 |
| Kale | Sow outdoors (spring) | Mar 22 – Apr 11 |
| Kale | Sow outdoors (fall) | Jul 23 – Aug 30 |
| Carrots | Sow outdoors (spring) | Apr 5 – May 21 |
| Carrots | Sow outdoors (fall) | Jun 30 – Aug 15 |
| Garlic | Plant outdoors (fall) | Oct 30 – Nov 30 |
Where these dates come from
ZIP code 85620 is matched to the NOAA station Sierra Vista, AZ, 39.1 km away, at 4,606 ft elevation (13 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Sierra Vista, AZ (used) | 4,606 ft | Apr 5 | Nov 9 |
| Bisbee 1Wnw, AZ | 5,560 ft | Apr 1 | Nov 10 |
| Coronado Nmem, AZ | 5,242 ft | Apr 7 | Nov 9 |
| Douglas Bisbee Inl Ap, AZ | 4,105 ft | Apr 11 | Nov 2 |
Frost dates near Naco
- Bisbee, AZ 85603 · last Apr 1, first Nov 10
- Mc Neal, AZ 85617 · last Mar 4, first Nov 29
- Hereford, AZ 85615 · last Apr 5, first Nov 9
- Sierra Vista, AZ 85650 · last Apr 5, first Nov 9
- Douglas, AZ 85608 · last Apr 11, first Nov 2
- Pirtleville, AZ 85626 · last Mar 18, first Nov 13
- Tombstone, AZ 85638 · last Mar 4, first Nov 29
- Fort Huachuca, AZ 85613 · last Apr 5, first Nov 9
Frequently asked questions
- When is the last frost in Naco, AZ?
- For ZIP code 85620, the average last spring frost (32°F) is April 5, based on NOAA 1991-2020 climate normals for the Sierra Vista, AZ weather station. There is a 1-in-10 chance of a frost after April 21.
- When is the first frost in Naco, 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 85620?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 216 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.