Frost dates for Conroe, TX
At Conroe, the median last spring frost (32°F) is Feb 24 and the median first fall frost is Dec 2, for a typical growing season of 285 days. For a 90% chance that the last frost has passed, wait until Mar 17. Nearby ZIP codes are in USDA hardiness zone 9a.
- Feb 24Last spring frost (median)50% chance of 32°F after this date
- Mar 17Safer planting date10% chance of 32°F after this date
- Dec 2First fall frost (median)50% chance of 32°F by this date
- 285 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 16 | Mar 9 | Mar 31 |
| 32°F | Jan 26 | Feb 24 | Mar 17 |
| 28°F | Dec 31 | Feb 2 | Mar 6 |
| 24°F | Dec 26 | Jan 22 | Mar 1 |
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 20 | Dec 8 |
| 32°F | Nov 11 | Dec 2 | Jan 2 |
| 28°F | Nov 24 | Dec 23 | Jan 28 |
| 24°F | Dec 7 | Jan 5 | Feb 13 |
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 | 226 days | 254 days | 284 days |
| 32°F | 253 days | 285 days | 324 days |
| 28°F | 280 days | 321 days | 365 days |
| 24°F | 311 days | 359 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 93% |
| 24°F | 58% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 77304 | 9a | 20 to 25°F | 3 km |
| 77384 | 9a | 20 to 25°F | 11 km |
| 77318 | 9a | 20 to 25°F | 14 km |
| 77385 | 9a | 20 to 25°F | 17 km |
| 77316 | 9a | 20 to 25°F | 20 km |
| 77356 | 9a | 20 to 25°F | 28 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 USC00411956, at 30.3303, -95.4831, elevation 75 m (245 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 16.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Conroe Montgomery Co Airport (7 km)
- Houston Hooks Mem Airport (30 km)
- Cleveland (38 km)
- Houston Intercont Airport (41 km)
- Huntsville (42 km)
- Huntsville Muni Airport (47 km)
- Washington State Park (65 km)
- Baytown (66 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.