Frost dates for San Antonio Stinson Airport, TX
At San Antonio Stinson Airport, the median last spring frost (32°F) is Feb 20 and the median first fall frost is Dec 3, for a typical growing season of 291 days. For a 90% chance that the last frost has passed, wait until Mar 13. Nearby ZIP codes are in USDA hardiness zone 9a.
- Feb 20Last spring frost (median)50% chance of 32°F after this date
- Mar 13Safer planting date10% chance of 32°F after this date
- Dec 3First fall frost (median)50% chance of 32°F by this date
- 291 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 8 | Mar 5 | Mar 27 |
| 32°F | Jan 20 | Feb 20 | Mar 13 |
| 28°F | Dec 25 | Jan 30 | Mar 5 |
| 24°F | Dec 20 | Jan 14 | Feb 20 |
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 2 | Nov 21 | Dec 9 |
| 32°F | Nov 12 | Dec 3 | Jan 1 |
| 28°F | Nov 24 | Dec 23 | Jan 24 |
| 24°F | Dec 9 | Jan 5 | Feb 5 |
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 | 261 days | 290 days |
| 32°F | 258 days | 291 days | 325 days |
| 28°F | 287 days | 330 days | 365 days |
| 24°F | 325 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 90% |
| 24°F | 50% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 78214 | 9a | 20 to 25°F | 1 km |
| 78235 | 9a | 20 to 25°F | 3 km |
| 78221 | 9a | 20 to 25°F | 5 km |
| 78210 | 9a | 20 to 25°F | 6 km |
| 78224 | 9a | 20 to 25°F | 8 km |
| 78222 | 9a | 20 to 25°F | 8 km |
| 78223 | 9a | 20 to 25°F | 9 km |
| 78263 | 9a | 20 to 25°F | 15 km |
| 78264 | 9a | 20 to 25°F | 16 km |
| 78112 | 9a | 20 to 25°F | 19 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 USW00012970, at 29.3389, -98.4719, elevation 174 m (571 ft).
- Data quality: Representative (10+ years), 19 years of freeze data.
- Average days per year at or below 32°F: 14.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- San Antonio Kelly AFB (12 km)
- San Antonio Incarnate Word (15 km)
- San Antonio Intl Airport (23 km)
- San Antonio/seaworld (26 km)
- Randolph AFB (30 km)
- Poteet (36 km)
- Floresville (38 km)
- Lytle 3w (38 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.