Frost dates for Tucson 17 NW, AZ
At Tucson 17 NW, the median last spring frost (32°F) is Feb 23 and the median first fall frost is Dec 6, for a typical growing season of 287 days. For a 90% chance that the last frost has passed, wait until Mar 22. Nearby ZIP codes are in USDA hardiness zone 9b.
- Feb 23Last spring frost (median)50% chance of 32°F after this date
- Mar 22Safer planting date10% chance of 32°F after this date
- Dec 6First fall frost (median)50% chance of 32°F by this date
- 287 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 22 | Mar 15 | Apr 10 |
| 32°F | Jan 15 | Feb 23 | Mar 22 |
| 28°F | Dec 19 | Jan 22 | Mar 1 |
| 24°F | Dec 13 | Jan 9 | Feb 12 |
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 7 | Nov 24 | Dec 10 |
| 32°F | Nov 18 | Dec 6 | Dec 25 |
| 28°F | Nov 30 | Dec 19 | Jan 22 |
| 24°F | Dec 10 | Jan 1 | Feb 3 |
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 | 219 days | 252 days | 282 days |
| 32°F | 254 days | 287 days | 324 days |
| 28°F | 294 days | 333 days | 365 days |
| 24°F | 329 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 87% |
| 24°F | 38% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 85743 | 9b | 25 to 30°F | 6 km |
| 85654 | 9b | 25 to 30°F | 18 km |
| 85653 | 9b | 25 to 30°F | 24 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 USC00028795, at 32.2542, -111.1961, elevation 781 m (2,561 ft).
- Data quality: Representative (10+ years), 23 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 11 W (3 km)
- Tucson U Of A #1 (18 km)
- Tohono Chul (22 km)
- Tucson WFO (23 km)
- Tucson Camp Ave Exp. (24 km)
- Tucson Intl Airport (26 km)
- Catalina State Park (31 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.