Frost dates for Cornwall, VT
At Cornwall, the median last spring frost (32°F) is May 5 and the median first fall frost is Oct 3, for a typical growing season of 151 days. For a 90% chance that the last frost has passed, wait until May 20. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- May 5Last spring frost (median)50% chance of 32°F after this date
- May 20Safer planting date10% chance of 32°F after this date
- Oct 3First fall frost (median)50% chance of 32°F by this date
- 151 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 | May 3 | May 18 | Jun 3 |
| 32°F | Apr 23 | May 5 | May 20 |
| 28°F | Apr 12 | Apr 26 | May 8 |
| 24°F | Apr 1 | Apr 14 | Apr 26 |
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 | Sep 10 | Sep 25 | Oct 6 |
| 32°F | Sep 21 | Oct 3 | Oct 19 |
| 28°F | Oct 1 | Oct 16 | Nov 1 |
| 24°F | Oct 10 | Oct 30 | Nov 14 |
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 | 108 days | 128 days | 148 days |
| 32°F | 131 days | 151 days | 169 days |
| 28°F | 152 days | 173 days | 195 days |
| 24°F | 175 days | 198 days | 218 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 |
|---|---|---|---|
| 05753 | 5a | -20 to -15°F | 5 km |
| 05778 | 5a | -20 to -15°F | 9 km |
| 05734 | 5a | -20 to -15°F | 10 km |
| 05770 | 5a | -20 to -15°F | 12 km |
| 05760 | 5a | -20 to -15°F | 19 km |
| 12960 | 4b | -25 to -20°F | 30 km |
| 12928 | 4b | -25 to -20°F | 30 km |
| 12883 | 4b | -25 to -20°F | 31 km |
| 12858 | 4b | -25 to -20°F | 40 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 USC00431580, at 43.9572, -73.2106, elevation 105 m (345 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 155.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Salisbury 2 N (10 km)
- S Lincoln (23 km)
- Vergennes (24 km)
- Rochester (34 km)
- Waitsfield 2 SE (41 km)
- Rutland (41 km)
- Northfield (50 km)
- Burlington Intl Airport (57 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.