Frost dates for Houston NWSO, TX
At Houston NWSO, the median last spring frost (32°F) is Jan 31 and the median first fall frost is Dec 14, for a typical growing season of 317 days. For a 90% chance that the last frost has passed, wait until Mar 5. Nearby ZIP codes are in USDA hardiness zone 9b.
- Jan 31Last spring frost (median)50% chance of 32°F after this date
- Mar 5Safer planting date10% chance of 32°F after this date
- Dec 14First fall frost (median)50% chance of 32°F by this date
- 317 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 21 | Feb 22 | Mar 17 |
| 32°F | Dec 25 | Jan 31 | Mar 5 |
| 28°F | Dec 19 | Jan 17 | Feb 24 |
| 24°F | Dec 22 | Jan 12 | 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 9 | Nov 29 | Dec 22 |
| 32°F | Nov 19 | Dec 14 | Jan 19 |
| 28°F | Dec 6 | Jan 3 | Feb 5 |
| 24°F | Dec 20 | Jan 9 | 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 | 249 days | 281 days | 315 days |
| 32°F | 279 days | 317 days | 357 days |
| 28°F | 317 days | 356 days | 365 days |
| 24°F | 351 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 94% |
| 28°F | 60% |
| 24°F | 21% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 77573 | 9b | 25 to 30°F | 4 km |
| 77539 | 9b | 25 to 30°F | 6 km |
| 77565 | 9b | 25 to 30°F | 9 km |
| 77598 | 9b | 25 to 30°F | 9 km |
| 77518 | 9b | 25 to 30°F | 10 km |
| 77058 | 9b | 25 to 30°F | 10 km |
| 77591 | 9b | 25 to 30°F | 11 km |
| 77586 | 9b | 25 to 30°F | 13 km |
| 77510 | 9b | 25 to 30°F | 14 km |
| 77568 | 9b | 25 to 30°F | 15 km |
| 77507 | 9b | 25 to 30°F | 17 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 USC00414333, at 29.4717, -95.0833, elevation 6 m (19 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 9.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Houston Clover Field (16 km)
- Alvin (19 km)
- Houston Hobby Airport (27 km)
- Galveston Scholes Field (31 km)
- Galveston (33 km)
- Houston-Port (36 km)
- Baytown (50 km)
- Angleton 2 W (51 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.