Frost dates for 85724Tucson, AZ
The average last spring frost in Tucson is February 20 and the average first fall frost is November 27, giving a typical growing season of about 280 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Feb 20
- Average first fall frost
- Nov 27
- Growing season
- 280 days
Safer after Mar 11 (1-in-10 risk)
Possible by Nov 10 (1-in-10 risk)
First frost typically in 26 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) | Feb 19 · Mar 12 · Apr 5 | Nov 1 · Nov 16 · Dec 1 | 247 days | 100% |
| Frost / freeze (32°F) | Jan 30 · Feb 20 · Mar 11 | Nov 10 · Nov 27 · Dec 12 | 280 days | 100% |
| Hard freeze (28°F) | Dec 29 · Jan 30 · Feb 24 | Nov 23 · Dec 10 · Jan 2 | 316 days | 98% |
Planting calendar for Tucson
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 | Jan 20 – Mar 28 |
| Tomatoes | Transplant outdoors | Mar 8 – Aug 7 |
| Peppers | Start seeds indoors | Jan 20 – Feb 20 |
| Peppers | Transplant outdoors | Mar 22 – Apr 22 |
| Eggplant | Start seeds indoors | Feb 6 – Mar 7 |
| Eggplant | Transplant outdoors | Mar 22 – Apr 22 |
| Cucumbers | Sow outdoors | Mar 22 – Aug 17 |
| Summer squash | Sow outdoors | Mar 8 – Apr 22 |
| Winter squash & pumpkins | Sow outdoors | Mar 22 – Apr 22 |
| Snap beans | Sow outdoors | Mar 8 – Sep 9 |
| Sweet corn | Sow outdoors | Mar 8 – Aug 7 |
| Watermelon & cantaloupe | Sow outdoors | Mar 22 – Apr 22 |
| Okra | Sow outdoors | Mar 15 – Apr 7 |
| Peas | Sow outdoors (spring) | Jan 20 – Mar 7 |
| Potatoes | Plant outdoors (spring) | Jan 20 – Mar 22 |
| Onions | Start seeds indoors (spring) | Dec 9 – Jan 5 |
| Onions | Transplant outdoors (spring) | Feb 6 – Mar 7 |
| Broccoli | Start seeds indoors (spring) | Jan 2 – Feb 5 |
| Broccoli | Transplant outdoors (spring) | Feb 6 – Mar 7 |
| Broccoli | Start seeds indoors (fall) | Jul 28 – Aug 7 |
| Broccoli | Transplant outdoors (fall) | Aug 27 – Sep 7 |
| Cabbage | Start seeds indoors (spring) | Dec 23 – Jan 20 |
| Cabbage | Transplant outdoors (spring) | Jan 20 – Feb 20 |
| Cabbage | Start seeds indoors (fall) | Jul 18 – Aug 17 |
| Cabbage | Transplant outdoors (fall) | Aug 17 – Sep 17 |
| Leaf lettuce | Sow outdoors (spring) | Jan 20 – Apr 7 |
| Leaf lettuce | Sow outdoors (fall) | Aug 17 – Oct 3 |
| Spinach | Sow outdoors (spring) | Jan 13 – Feb 26 |
| Spinach | Sow outdoors (fall) | Sep 3 – Oct 8 |
| Radishes | Sow outdoors (spring) | Jan 20 – Mar 12 |
| Radishes | Sow outdoors (fall) | Aug 17 – Oct 18 |
| Kale | Sow outdoors (spring) | Feb 6 – Feb 26 |
| Kale | Sow outdoors (fall) | Aug 10 – Sep 17 |
| Carrots | Sow outdoors (spring) | Feb 20 – Apr 7 |
| Carrots | Sow outdoors (fall) | Jul 18 – Sep 2 |
| Garlic | Plant outdoors (fall) | Nov 17 – Dec 18 |
Where these dates come from
ZIP code 85724 is matched to the NOAA station Tucson Camp Ave Exp, AZ, 4.6 km away, at 2,330 ft elevation (114 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Tucson Camp Ave Exp, AZ (used) | 2,330 ft | Feb 20 | Nov 27 |
| Tucson Wfo, AZ | 2,435 ft | Jan 20 | Dec 17 |
| Tucson U Of A #1, AZ | 2,315 ft | Feb 11 | Dec 2 |
| Tohono Chul, AZ | 2,527 ft | Feb 26 | Dec 4 |
Frost dates near Tucson
- Tucson, AZ 85719 · last Feb 20, first Nov 27
- Mount Lemmon, AZ 85619 · last Mar 23, first Nov 22
- Cortaro, AZ 85652 · last Feb 11, first Dec 2
- Rillito, AZ 85654 · last Feb 11, first Dec 2
- Marana, AZ 85658 · last Feb 11, first Dec 2
- Catalina, AZ 85738 · last Apr 2, first Nov 11
- Sahuarita, AZ 85629 · last Feb 25, first Nov 27
- Vail, AZ 85641 · last Jan 26, first Dec 16
Frequently asked questions
- When is the last frost in Tucson, AZ?
- For ZIP code 85724, the average last spring frost (32°F) is February 20, based on NOAA 1991-2020 climate normals for the Tucson Camp Ave Exp, AZ weather station. There is a 1-in-10 chance of a frost after March 11.
- When is the first frost in Tucson, AZ?
- The average first fall frost (32°F) is November 27. There is a 1-in-10 chance of frost by November 10, so tender plants are at risk from that point on.
- How long is the growing season in 85724?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 280 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.