Frost dates for 85755Tucson, AZ
The average last spring frost in Tucson is April 2 and the average first fall frost is November 11, giving a typical growing season of about 222 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 2
- Average first fall frost
- Nov 11
- Growing season
- 222 days
Safer after Apr 18 (1-in-10 risk)
Possible by Oct 26 (1-in-10 risk)
First frost typically in 8 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 4 · Apr 18 · May 5 | Oct 18 · Nov 1 · Nov 17 | 195 days | 100% |
| Frost / freeze (32°F) | Mar 16 · Apr 2 · Apr 18 | Oct 26 · Nov 11 · Nov 29 | 222 days | 100% |
| Hard freeze (28°F) | Feb 22 · Mar 12 · Apr 1 | Nov 3 · Nov 21 · Dec 10 | 252 days | 100% |
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 | Mar 2 – May 8 |
| Tomatoes | Transplant outdoors | Apr 18 – Jul 22 |
| Peppers | Start seeds indoors | Mar 2 – Apr 2 |
| Peppers | Transplant outdoors | May 2 – Jun 2 |
| Eggplant | Start seeds indoors | Mar 19 – Apr 17 |
| Eggplant | Transplant outdoors | May 2 – Jun 2 |
| Cucumbers | Sow outdoors | May 2 – Aug 1 |
| Summer squash | Sow outdoors | Apr 18 – Jun 2 |
| Winter squash & pumpkins | Sow outdoors | May 2 – Jun 2 |
| Snap beans | Sow outdoors | Apr 18 – Aug 24 |
| Sweet corn | Sow outdoors | Apr 18 – Jul 22 |
| Watermelon & cantaloupe | Sow outdoors | May 2 – Jun 2 |
| Okra | Sow outdoors | Apr 25 – May 18 |
| Peas | Sow outdoors (spring) | Mar 2 – Apr 17 |
| Potatoes | Plant outdoors (spring) | Mar 2 – May 2 |
| Onions | Start seeds indoors (spring) | Jan 19 – Feb 15 |
| Onions | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (spring) | Feb 12 – Mar 18 |
| Broccoli | Transplant outdoors (spring) | Mar 19 – Apr 17 |
| Broccoli | Start seeds indoors (fall) | Jul 12 – Jul 22 |
| Broccoli | Transplant outdoors (fall) | Aug 11 – Aug 22 |
| Cabbage | Start seeds indoors (spring) | Feb 2 – Mar 2 |
| Cabbage | Transplant outdoors (spring) | Mar 2 – Apr 2 |
| Cabbage | Start seeds indoors (fall) | Jul 2 – Aug 1 |
| Cabbage | Transplant outdoors (fall) | Aug 1 – Sep 1 |
| Leaf lettuce | Sow outdoors (spring) | Mar 2 – May 18 |
| Leaf lettuce | Sow outdoors (fall) | Aug 1 – Sep 17 |
| Spinach | Sow outdoors (spring) | Feb 23 – Apr 8 |
| Spinach | Sow outdoors (fall) | Aug 18 – Sep 22 |
| Radishes | Sow outdoors (spring) | Mar 2 – Apr 22 |
| Radishes | Sow outdoors (fall) | Aug 1 – Oct 2 |
| Kale | Sow outdoors (spring) | Mar 19 – Apr 8 |
| Kale | Sow outdoors (fall) | Jul 25 – Sep 1 |
| Carrots | Sow outdoors (spring) | Apr 2 – May 18 |
| Carrots | Sow outdoors (fall) | Jul 2 – Aug 17 |
| Garlic | Plant outdoors (fall) | Nov 1 – Dec 2 |
Where these dates come from
ZIP code 85755 is matched to the NOAA station Catalina Sp, AZ, 4.4 km away, at 2,707 ft elevation (59 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Catalina Sp, AZ (used) | 2,707 ft | Apr 2 | Nov 11 |
| Tohono Chul, AZ | 2,527 ft | Feb 26 | Dec 4 |
| Tucson Camp Ave Exp, AZ | 2,330 ft | Feb 20 | Nov 27 |
| Tucson U Of A #1, AZ | 2,315 ft | Feb 11 | Dec 2 |
Frost dates near Tucson
- Tucson, AZ 85737 · last Apr 2, first Nov 11
- Catalina, AZ 85738 · last Apr 2, first Nov 11
- Cortaro, AZ 85652 · last Feb 11, first Dec 2
- Marana, AZ 85658 · last Feb 11, first Dec 2
- Rillito, AZ 85654 · last Feb 11, first Dec 2
- Mount Lemmon, AZ 85619 · last Mar 23, first Nov 22
- Oracle, AZ 85623 · last Mar 23, first Nov 22
- Red Rock, AZ 85145 · last Feb 6, first Dec 9
Frequently asked questions
- When is the last frost in Tucson, AZ?
- For ZIP code 85755, the average last spring frost (32°F) is April 2, based on NOAA 1991-2020 climate normals for the Catalina Sp, AZ weather station. There is a 1-in-10 chance of a frost after April 18.
- When is the first frost in Tucson, AZ?
- The average first fall frost (32°F) is November 11. There is a 1-in-10 chance of frost by October 26, so tender plants are at risk from that point on.
- How long is the growing season in 85755?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 222 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.