New Hampshire frost dates
Across 54 weather stations in New Hampshire, the median last spring frost runs from Apr 21 in Manchester Airport to May 31 in Colebrook, and the first fall frost from Sep 18 to Oct 19.
New Hampshire at a glance
- Weather stations
- 54
- Earliest last frost
- Apr 21 Manchester Airport
- Latest last frost
- May 31 Colebrook
- Longest season
- 180 days Manchester Airport
- Typical season
- about 148 frost-free days
- Hardiness zones
- Zones 4a to 6a
Frost dates by weather station
| Weather station | Last spring frost | First fall frost | Frost-free days | Zone |
|---|---|---|---|---|
| Benton | May 15 | Sep 28 | 133 | 5a |
| Berlin | May 14 | Sep 30 | 135 | 4b |
| Berlin Municipal Airport | May 30 | Sep 19 | 112 | 4b |
| Bethlehem | May 24 | Sep 18 | 116 | 5a |
| Bradford | May 15 | Sep 27 | 135 | 5b |
| Colebrook | May 31 | Sep 21 | 112 | 4a |
| Concord Municipal Airport | May 8 | Oct 3 | 146 | 5b |
| Durham | May 8 | Oct 4 | 148 | 6a |
| Durham 2 mi N | May 3 | Oct 10 | 158 | 6a |
| Durham 2 mi SSW | May 7 | Oct 4 | 150 | 6a |
| East Milford | Apr 28 | Oct 8 | 161 | 6a |
| East Sandwich | May 6 | Oct 6 | 151 | 5a |
| Epping | May 7 | Oct 4 | 148 | 6a |
| Errol Airport | May 21 | Sep 22 | 123 | 4a |
| First Connecticut Lake | May 25 | Sep 24 | 121 | 4a |
| Franklin Falls Dam | May 7 | Oct 3 | 148 | 5b |
| Gorham Airport | May 14 | Sep 26 | 133 | 5a |
| Grafton | May 21 | Sep 26 | 127 | 5a |
| Greenland | May 4 | Oct 8 | 157 | 6a |
| Greenville | May 10 | Oct 6 | 147 | 6a |
| Hanover | May 1 | Oct 13 | 162 | 5a |
| Hopkinton Lake | May 6 | Oct 1 | 146 | 5b |
| Hudson | May 3 | Oct 8 | 156 | 6a |
| Jaffrey Municipal Airport | May 5 | Oct 6 | 152 | 6a |
| Jaffrey Silver Ranch Airpark | May 5 | Oct 6 | 154 | 6a |
| Jefferson | May 8 | Oct 1 | 146 | 4b |
| Keene | May 14 | Oct 1 | 138 | 5b |
| Lakeport | Apr 30 | Oct 18 | 170 | 5b |
| Lancaster | May 18 | Sep 30 | 132 | 4b |
| Lebanon Municipal Airport | May 9 | Oct 6 | 148 | 5a |
| Lincoln Nepp | May 7 | Oct 4 | 149 | 5a |
| Manchester Airport | Apr 21 | Oct 19 | 180 | 6a |
| Massabesic Lake | Apr 30 | Oct 11 | 164 | 6a |
| Meredith | Apr 28 | Oct 16 | 171 | 5b |
| Milford | May 3 | Oct 5 | 156 | 6a |
| Mount Sunapee | May 2 | Oct 9 | 158 | 5b |
| Nashua | Apr 30 | Oct 12 | 165 | 6a |
| Nashua Cwsu | Apr 29 | Oct 8 | 162 | 6a |
| Newport | May 14 | Oct 1 | 140 | 5a |
| North Conway | May 7 | Oct 5 | 150 | 5a |
| North Stratford | May 19 | Sep 29 | 131 | 4a |
| Pinkham Notch | May 18 | Oct 1 | 135 | 5a |
| Plymouth | May 20 | Sep 27 | 128 | 5b |
| Rochester Skyhaven Airport | Apr 30 | Oct 9 | 161 | 6a |
| Salisbury | May 14 | Sep 29 | 138 | 5b |
| Tamworth | May 16 | Sep 26 | 129 | 5a |
| Walpole Nepp | May 8 | Oct 3 | 149 | 5b |
| Waterville Valley Nepp | May 15 | Sep 28 | 134 | 5a |
| Weare | May 2 | Oct 8 | 158 | 6a |
| Weare 2 mi NE | May 9 | Oct 5 | 148 | 6a |
| Wentworth | May 12 | Oct 6 | 146 | 5a |
| West Hampstead | Apr 30 | Oct 11 | 162 | 6a |
| Whitefield Mount Washington Airport | May 27 | Sep 19 | 116 | 4b |
| York Pond | May 23 | Sep 22 | 122 | 4b |
Median dates from NOAA 1991–2020 climate normals. How to read them.