Frost dates for Amistad Dam, TX
At Amistad Dam, the median last spring frost (32°F) is Feb 14 and the median first fall frost is Dec 6, for a typical growing season of 297 days. For a 90% chance that the last frost has passed, wait until Mar 9. Nearby ZIP codes are in USDA hardiness zone 9a.
- Feb 14Last spring frost (median)50% chance of 32°F after this date
- Mar 9Safer planting date10% chance of 32°F after this date
- Dec 6First fall frost (median)50% chance of 32°F by this date
- 297 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 9 | Mar 1 | Mar 20 |
| 32°F | Jan 15 | Feb 14 | Mar 9 |
| 28°F | Dec 21 | Jan 26 | Feb 28 |
| 24°F | Dec 13 | Jan 8 | Feb 10 |
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 4 | Nov 24 | Dec 11 |
| 32°F | Nov 16 | Dec 6 | Jan 1 |
| 28°F | Nov 29 | Dec 22 | Jan 27 |
| 24°F | Dec 8 | Jan 1 | Feb 2 |
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 | 239 days | 268 days | 293 days |
| 32°F | 264 days | 297 days | 332 days |
| 28°F | 297 days | 335 days | 365 days |
| 24°F | 334 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 86% |
| 24°F | 45% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 78842 | 9a | 20 to 25°F | 20 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 USC00410225, at 29.4608, -101.0286, elevation 353 m (1,157 ft).
- Data quality: Representative (10+ years), 24 years of freeze data.
- Average days per year at or below 32°F: 12.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Del Rio 4nw (11 km)
- Del Rio Intl Airport (13 km)
- Carta Valley (50 km)
- Brackettville 22 N (58 km)
- Brackettville (62 km)
- Hudspeth River Rch (62 km)
- Langtry (64 km)
- Eagle Pass 3n (95 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.