Frost dates for Oak Ridge Asos, TN
At Oak Ridge Asos, the median last spring frost (32°F) is Mar 31 and the median first fall frost is Nov 4, for a typical growing season of 218 days. For a 90% chance that the last frost has passed, wait until Apr 15. Nearby ZIP codes are in USDA hardiness zones 7a to 7b.
- Mar 31Last spring frost (median)50% chance of 32°F after this date
- Apr 15Safer planting date10% chance of 32°F after this date
- Nov 4First fall frost (median)50% chance of 32°F by this date
- 218 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 | Mar 28 | Apr 12 | Apr 30 |
| 32°F | Mar 11 | Mar 31 | Apr 15 |
| 28°F | Feb 26 | Mar 18 | Apr 3 |
| 24°F | Feb 9 | Mar 4 | Mar 23 |
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 | Oct 14 | Oct 27 | Nov 8 |
| 32°F | Oct 22 | Nov 4 | Nov 18 |
| 28°F | Nov 1 | Nov 15 | Dec 4 |
| 24°F | Nov 11 | Dec 1 | Dec 23 |
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 | 173 days | 196 days | 216 days |
| 32°F | 198 days | 218 days | 241 days |
| 28°F | 219 days | 243 days | 268 days |
| 24°F | 244 days | 272 days | 303 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 37716 | 7b | 5 to 10°F | 11 km |
| 37931 | 7b | 5 to 10°F | 11 km |
| 37840 | 7b | 5 to 10°F | 13 km |
| 37710 | 7a | 0 to 5°F | 17 km |
| 37849 | 7b | 5 to 10°F | 17 km |
| 37845 | 7a | 0 to 5°F | 21 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 USW00053868, at 36.0236, -84.2375, elevation 277 m (910 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 68.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Oak Ridge Atdd (3 km)
- Lenoir City (26 km)
- Norris (26 km)
- Knoxville Exp. Station (29 km)
- Kingston (32 km)
- Knoxville McGhee Tyson Airport (32 km)
- Rockwood 2 (46 km)
- Lancing 6 NW (46 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.