Frost dates for N Conway, NH
At N Conway, the median last spring frost (32°F) is May 7 and the median first fall frost is Oct 5, for a typical growing season of 150 days. For a 90% chance that the last frost has passed, wait until May 19. Nearby ZIP codes are in USDA hardiness zones 5a to 5b.
- May 7Last spring frost (median)50% chance of 32°F after this date
- May 19Safer planting date10% chance of 32°F after this date
- Oct 5First fall frost (median)50% chance of 32°F by this date
- 150 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 6 | May 18 | May 31 |
| 32°F | Apr 27 | May 7 | May 19 |
| 28°F | Apr 13 | Apr 26 | May 9 |
| 24°F | Apr 2 | Apr 11 | 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 13 | Sep 26 | Oct 7 |
| 32°F | Sep 23 | Oct 5 | Oct 20 |
| 28°F | Oct 1 | Oct 17 | Nov 4 |
| 24°F | Oct 13 | Nov 1 | Nov 15 |
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 | 113 days | 130 days | 146 days |
| 32°F | 132 days | 150 days | 168 days |
| 28°F | 154 days | 174 days | 195 days |
| 24°F | 179 days | 200 days | 219 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 |
|---|---|---|---|
| 03860 | 5a | -20 to -15°F | 2 km |
| 03847 | 5b | -15 to -10°F | 2 km |
| 03845 | 5a | -20 to -15°F | 5 km |
| 03838 | 5a | -20 to -15°F | 10 km |
| 03813 | 5a | -20 to -15°F | 10 km |
| 03812 | 5a | -20 to -15°F | 14 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 USC00275995, at 44.0561, -71.1297, elevation 159 m (522 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 172.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Tamworth 4 (24 km)
- Pinkham Notch (25 km)
- Mount Washington (27 km)
- E Sandwich (32 km)
- Waterville Valley Nepp (33 km)
- Gorham Airport (38 km)
- Lincoln Nepp (43 km)
- Berlin (44 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.