Frost dates for Rio Grande City, TX
At Rio Grande City, the median last spring frost (32°F) is Jan 31 and the median first fall frost is Dec 17, for a typical growing season of 321 days. For a 90% chance that the last frost has passed, wait until Mar 4. Nearby ZIP codes are in USDA hardiness zones 9b to 10a.
- Jan 31Last spring frost (median)50% chance of 32°F after this date
- Mar 4Safer planting date10% chance of 32°F after this date
- Dec 17First fall frost (median)50% chance of 32°F by this date
- 321 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 | Jan 22 | Feb 22 | Mar 14 |
| 32°F | Dec 29 | Jan 31 | Mar 4 |
| 28°F | Dec 13 | Jan 12 | Feb 20 |
| 24°F | Dec 11 | Jan 3 | 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 | Dec 1 | Dec 28 |
| 32°F | Nov 22 | Dec 17 | Jan 20 |
| 28°F | Dec 2 | Dec 29 | Feb 1 |
| 24°F | Dec 8 | Jan 1 | Feb 1 |
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 | 255 days | 285 days | 319 days |
| 32°F | 283 days | 321 days | 358 days |
| 28°F | 313 days | 357 days | 365 days |
| 24°F | 350 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 93% |
| 28°F | 60% |
| 24°F | 23% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 78547 | 9b | 25 to 30°F | 14 km |
| 78582 | 9b | 25 to 30°F | 19 km |
| 78548 | 10a | 30 to 35°F | 19 km |
| 78591 | 9b | 25 to 30°F | 39 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 USC00417622, at 26.3769, -98.8117, elevation 52 m (172 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 6.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Falcon Dam (38 km)
- La Joya (49 km)
- McAllen (60 km)
- McAllen Miller Intl Airport (60 km)
- Edinburg (66 km)
- Zapata 1 S (70 km)
- McCook (72 km)
- San Manuel (72 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.