Frost dates for Nashua Cwsu, NH
At Nashua Cwsu, the median last spring frost (32°F) is Apr 29 and the median first fall frost is Oct 8, for a typical growing season of 162 days. For a 90% chance that the last frost has passed, wait until May 11. Nearby ZIP codes are in USDA hardiness zone 6a.
- Apr 29Last spring frost (median)50% chance of 32°F after this date
- May 11Safer planting date10% chance of 32°F after this date
- Oct 8First fall frost (median)50% chance of 32°F by this date
- 162 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 29 | May 10 | May 23 |
| 32°F | Apr 16 | Apr 29 | May 11 |
| 28°F | Apr 3 | Apr 16 | Apr 28 |
| 24°F | Mar 22 | Apr 4 | Apr 16 |
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 21 | Oct 1 | Oct 12 |
| 32°F | Sep 28 | Oct 8 | Oct 25 |
| 28°F | Oct 6 | Oct 20 | Nov 5 |
| 24°F | Oct 15 | Nov 2 | Nov 16 |
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 | 125 days | 143 days | 159 days |
| 32°F | 145 days | 162 days | 180 days |
| 28°F | 166 days | 185 days | 204 days |
| 24°F | 188 days | 209 days | 228 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 |
|---|---|---|---|
| 03060 | 6a | -10 to -5°F | 2 km |
| 03062 | 6a | -10 to -5°F | 2 km |
| 01827 | 6a | -10 to -5°F | 7 km |
| 03049 | 6a | -10 to -5°F | 9 km |
| 01463 | 6a | -10 to -5°F | 12 km |
| 01450 | 6a | -10 to -5°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 USC00275703, at 42.7347, -71.4803, elevation 55 m (180 ft).
- Data quality: Estimated from nearby stations (2+ years), 6 years of freeze data.
- Average days per year at or below 32°F: 149.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Nashua 2 NNW (6 km)
- Hudson 1 SSE (8 km)
- E Milford (16 km)
- Milford (18 km)
- Manchester Airport (22 km)
- Greenville 1 NNE (27 km)
- Massabesic Lake (29 km)
- W Hampstead (30 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.