Frost dates for Tucson 11 W, AZ
At Tucson 11 W, the median last spring frost (32°F) is Feb 8 and the median first fall frost is Dec 10, for a typical growing season of 303 days. For a 90% chance that the last frost has passed, wait until Mar 8. Nearby ZIP codes are in USDA hardiness zone 9a.
- Feb 8Last spring frost (median)50% chance of 32°F after this date
- Mar 8Safer planting date10% chance of 32°F after this date
- Dec 10First fall frost (median)50% chance of 32°F by this date
- 303 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Feb 6 | Mar 4 | Mar 29 |
| 32°F | Jan 6 | Feb 8 | Mar 8 |
| 28°F | Dec 15 | Jan 20 | Feb 18 |
| 24°F | Dec 14 | Jan 14 | Feb 8 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Nov 11 | Nov 29 | Dec 13 |
| 32°F | Nov 22 | Dec 10 | Jan 3 |
| 28°F | Nov 30 | Dec 27 | Feb 1 |
| 24°F | Dec 13 | Jan 11 | Feb 7 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 235 days | 266 days | 298 days |
| 32°F | 270 days | 303 days | 339 days |
| 28°F | 310 days | 345 days | 365 days |
| 24°F | 342 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 99% |
| 28°F | 74% |
| 24°F | 24% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85757 | 9a | 20 to 25°F | 13 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USW00053131, at 32.2394, -111.1697, elevation 833 m (2,733 ft).
- Data quality: Representative (10+ years), 18 years of freeze data.
- Average days per year at or below 32°F: 11.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Tucson 17 NW (3 km)
- Tucson U Of A #1 (16 km)
- Tucson WFO (20 km)
- Tohono Chul (21 km)
- Tucson Camp Ave Exp. (22 km)
- Tucson Intl Airport (23 km)
- Catalina State Park (30 km)
- Anvil Rch (35 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.