Frost dates for Mount Vernon, KY
At Mount Vernon, the median last spring frost (32°F) is Apr 18 and the median first fall frost is Oct 24, for a typical growing season of 189 days. For a 90% chance that the last frost has passed, wait until May 6. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 18Last spring frost (median)50% chance of 32°F after this date
- May 6Safer planting date10% chance of 32°F after this date
- Oct 24First fall frost (median)50% chance of 32°F by this date
- 189 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 | Apr 14 | Apr 30 | May 16 |
| 32°F | Mar 31 | Apr 18 | May 6 |
| 28°F | Mar 18 | Apr 2 | Apr 21 |
| 24°F | Mar 2 | Mar 22 | Apr 7 |
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 3 | Oct 15 | Oct 27 |
| 32°F | Oct 13 | Oct 24 | Nov 5 |
| 28°F | Oct 22 | Nov 4 | Nov 18 |
| 24°F | Nov 2 | Nov 15 | Dec 4 |
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 | 149 days | 169 days | 187 days |
| 32°F | 167 days | 189 days | 211 days |
| 28°F | 190 days | 213 days | 237 days |
| 24°F | 214 days | 238 days | 262 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 |
|---|---|---|---|
| 40456 | 7a | 0 to 5°F | 2 km |
| 40460 | 7a | 0 to 5°F | 9 km |
| 40409 | 7a | 0 to 5°F | 9 km |
| 40445 | 7a | 0 to 5°F | 11 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 USC00155648, at 37.3542, -84.3369, elevation 354 m (1,160 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 101.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Crab Orchard 6 N (18 km)
- Berea College (25 km)
- Somerset 2 N (36 km)
- London Corbin Airport (38 km)
- Eastern Kentucky Univ (44 km)
- Booneville 12sw (50 km)
- Danville (51 km)
- Manchester 4 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.