Frost dates for Mount Carmel, CT
At Mount Carmel, the median last spring frost (32°F) is Apr 18 and the median first fall frost is Oct 26, for a typical growing season of 191 days. For a 90% chance that the last frost has passed, wait until May 3. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Apr 18Last spring frost (median)50% chance of 32°F after this date
- May 3Safer planting date10% chance of 32°F after this date
- Oct 26First fall frost (median)50% chance of 32°F by this date
- 191 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 18 | May 1 | May 16 |
| 32°F | Apr 5 | Apr 18 | May 3 |
| 28°F | Mar 23 | Apr 5 | Apr 19 |
| 24°F | Mar 11 | Mar 26 | Apr 6 |
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 2 | Oct 15 | Oct 30 |
| 32°F | Oct 11 | Oct 26 | Nov 9 |
| 28°F | Oct 22 | Nov 6 | Nov 22 |
| 24°F | Nov 2 | Nov 19 | Dec 6 |
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 | 148 days | 166 days | 186 days |
| 32°F | 172 days | 191 days | 208 days |
| 28°F | 195 days | 214 days | 235 days |
| 24°F | 217 days | 238 days | 261 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 |
|---|---|---|---|
| 06518 | 6b | -5 to 0°F | 3 km |
| 06514 | 6b | -5 to 0°F | 5 km |
| 06473 | 6b | -5 to 0°F | 5 km |
| 06517 | 7a | 0 to 5°F | 6 km |
| 06524 | 6b | -5 to 0°F | 8 km |
| 06472 | 6b | -5 to 0°F | 11 km |
| 06712 | 6b | -5 to 0°F | 12 km |
| 06770 | 6b | -5 to 0°F | 15 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 USC00065077, at 41.4078, -72.9028, elevation 55 m (180 ft).
- Data quality: Representative (10+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 123.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Meriden Markham Muni Airport (13 km)
- New Haven Tweed Airport (16 km)
- Ansonia 1 NE (17 km)
- Bridgeport Sikorsky Mem Airport (34 km)
- Hartford Brainard Field (42 km)
- Burlington (43 km)
- Danbury (43 km)
- Danbury Muni Airport (49 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.