Frost dates for Saint Johnsbury, VT
At Saint Johnsbury, the median last spring frost (32°F) is May 10 and the median first fall frost is Oct 3, for a typical growing season of 147 days. For a 90% chance that the last frost has passed, wait until May 23. Nearby ZIP codes are in USDA hardiness zone 4b.
- May 10Last spring frost (median)50% chance of 32°F after this date
- May 23Safer planting date10% chance of 32°F after this date
- Oct 3First fall frost (median)50% chance of 32°F by this date
- 147 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 8 | May 22 | Jun 4 |
| 32°F | Apr 27 | May 10 | May 23 |
| 28°F | Apr 16 | Apr 27 | May 10 |
| 24°F | Apr 5 | Apr 14 | Apr 25 |
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 23 | Oct 4 |
| 32°F | Sep 21 | Oct 3 | Oct 17 |
| 28°F | Oct 2 | Oct 15 | Nov 2 |
| 24°F | Oct 13 | Oct 29 | Nov 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 | 105 days | 123 days | 141 days |
| 32°F | 128 days | 147 days | 166 days |
| 28°F | 152 days | 171 days | 191 days |
| 24°F | 177 days | 197 days | 214 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 05819 | 4b | -25 to -20°F | 3 km |
| 05828 | 4b | -25 to -20°F | 9 km |
| 05821 | 4b | -25 to -20°F | 13 km |
| 03771 | 4b | -25 to -20°F | 14 km |
| 05851 | 4b | -25 to -20°F | 14 km |
| 05824 | 4b | -25 to -20°F | 15 km |
| 05873 | 4b | -25 to -20°F | 16 km |
| 05850 | 4b | -25 to -20°F | 16 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 USW00054742, at 44.4200, -72.0194, elevation 213 m (700 ft).
- Data quality: Representative (10+ years), 22 years of freeze data.
- Average days per year at or below 32°F: 167.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Saint Johnsbury (0 km)
- Sutton (21 km)
- E Haven (27 km)
- Sutton 2ne (27 km)
- Plainfield (35 km)
- Island Pond Airport (44 km)
- Island Pond (45 km)
- Worcester 2 W (45 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.