Frost dates for Mammoth Cave, KY
At Mammoth Cave, the median last spring frost (32°F) is Apr 9 and the median first fall frost is Oct 30, for a typical growing season of 204 days. For a 90% chance that the last frost has passed, wait until Apr 29. Nearby ZIP codes are in USDA hardiness zone 7a.
- Apr 9Last spring frost (median)50% chance of 32°F after this date
- Apr 29Safer planting date10% chance of 32°F after this date
- Oct 30First fall frost (median)50% chance of 32°F by this date
- 204 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 6 | Apr 22 | May 9 |
| 32°F | Mar 21 | Apr 9 | Apr 29 |
| 28°F | Mar 5 | Mar 27 | Apr 12 |
| 24°F | Feb 20 | Mar 13 | Mar 31 |
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 6 | Oct 20 | Oct 31 |
| 32°F | Oct 17 | Oct 30 | Nov 12 |
| 28°F | Oct 28 | Nov 8 | Nov 26 |
| 24°F | Nov 5 | Nov 20 | Dec 11 |
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 | 159 days | 180 days | 201 days |
| 32°F | 179 days | 204 days | 227 days |
| 28°F | 207 days | 230 days | 255 days |
| 24°F | 229 days | 254 days | 283 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 |
|---|---|---|---|
| 42160 | 7a | 0 to 5°F | 6 km |
| 42163 | 7a | 0 to 5°F | 6 km |
| 42171 | 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 USC00155097, at 37.1317, -86.1481, elevation 232 m (760 ft).
- Data quality: Representative (10+ years), 27 years of freeze data.
- Average days per year at or below 32°F: 78.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bowling Green 21 NNE (15 km)
- Nolin River Lake (19 km)
- Glasgow (26 km)
- Barren River Lake (26 km)
- Bowling Green Warren Co Airport (31 km)
- Millerstown 4e (36 km)
- Knob Lick 4s (42 km)
- Scottsville (43 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.