New Hampshire frost dates
The typical last spring frost ranges from Apr 30 in Manchester to May 8 in Concord.
4 of the 4 New Hampshire cities listed have typical frost dates. The longest frost-free season is 165 days in Nashua; the shortest is 146 days in Concord. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Concord | May 8 | May 22 | Oct 3 | Sep 21 | Apr 27 / Oct 13 | 146 days |
| Manchester | Apr 30 | May 14 | Oct 11 | Sep 30 | Apr 17 / Oct 24 | 164 days |
| Nashua | Apr 30 | May 11 | Oct 12 | Sep 30 | Apr 17 / Oct 24 | 165 days |
| North Conway | May 7 | May 19 | Oct 5 | Sep 23 | Apr 26 / Oct 17 | 150 days |
Reading the table: North Conway
In North Conway, the last spring frost typically comes around May 7: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 19, 12 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Oct 5, and in 1 year in 10 before Sep 23. Hard freezes (28°F) usually end earlier in spring and start later in fall: around Apr 26 and Oct 17 in North Conway.
Frost dates at more New Hampshire weather stations
NOAA stations across New Hampshire used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Benton 5 Sw | 1,200 ft | May 15 (1 in 10 after Jun 3) | Sep 28 (before Sep 12) |
| Berlin Muni Airport | 1,158 ft | May 30 (1 in 10 after Jun 11) | Sep 19 (before Sep 5) |
| Bethlehem 2 | 1,180 ft | May 24 (1 in 10 after Jun 8) | Sep 18 (before Sep 6) |
| Durham | 75 ft | May 8 (1 in 10 after May 22) | Oct 4 (before Sep 23) |
| Durham 2 N | 119 ft | May 3 (1 in 10 after May 16) | Oct 10 (before Sep 27) |
| Durham 2 Ssw | 63 ft | May 7 (1 in 10 after May 19) | Oct 4 (before Sep 23) |
| Epping | 160 ft | May 7 (1 in 10 after May 21) | Oct 4 (before Sep 22) |
| First Connecticut Lake | 1,650 ft | May 25 (1 in 10 after Jun 8) | Sep 24 (before Sep 9) |
| Grafton | 830 ft | May 21 (1 in 10 after Jun 5) | Sep 26 (before Sep 12) |
| Greenland | 95 ft | May 4 (1 in 10 after May 18) | Oct 8 (before Sep 27) |
| Greenville 1 Nne | 900 ft | May 10 (1 in 10 after May 27) | Oct 6 (before Sep 25) |
| Hanover | 584 ft | May 1 (1 in 10 after May 15) | Oct 13 (before Oct 1) |
| Hudson 1 Sse | 185 ft | May 3 (1 in 10 after May 16) | Oct 8 (before Sep 27) |
| Jaffrey Muni Airport | 1,040 ft | May 5 (1 in 10 after May 20) | Oct 6 (before Sep 25) |
| Keene | 511 ft | May 14 (1 in 10 after May 28) | Oct 1 (before Sep 18) |
| Lakeport 2 | 500 ft | Apr 30 (1 in 10 after May 13) | Oct 18 (before Oct 4) |
| Lancaster | 860 ft | May 18 (1 in 10 after Jun 1) | Sep 30 (before Sep 16) |
| Lebanon Muni Airport | 598 ft | May 9 (1 in 10 after May 24) | Oct 6 (before Sep 23) |
| Manchester Airport | 225 ft | Apr 21 (1 in 10 after May 6) | Oct 19 (before Oct 4) |
| Milford | 320 ft | May 3 (1 in 10 after May 15) | Oct 5 (before Sep 25) |
| Mt Sunapee | 1,275 ft | May 2 (1 in 10 after May 17) | Oct 9 (before Sep 27) |
| Newport | 770 ft | May 14 (1 in 10 after May 29) | Oct 1 (before Sep 19) |
| Pinkham Notch | 2,025 ft | May 18 (1 in 10 after Jun 1) | Oct 1 (before Sep 15) |
| Plymouth | 660 ft | May 20 (1 in 10 after Jun 4) | Sep 27 (before Sep 14) |
| Rochester Skyhaven Airport | 323 ft | Apr 30 (1 in 10 after May 13) | Oct 9 (before Sep 27) |
| Salisbury | 550 ft | May 14 (1 in 10 after May 28) | Sep 29 (before Sep 14) |
| Tamworth 4 | 541 ft | May 16 (1 in 10 after May 30) | Sep 26 (before Sep 10) |
| W Hampstead | 288 ft | Apr 30 (1 in 10 after May 14) | Oct 11 (before Sep 29) |
| Waterville Valley Nepp | 1,429 ft | May 15 (1 in 10 after May 29) | Sep 28 (before Sep 13) |
| Weare | 720 ft | May 2 (1 in 10 after May 14) | Oct 8 (before Sep 27) |
| Whitefield Mt Washington Airport | 1,074 ft | May 27 (1 in 10 after Jun 10) | Sep 19 (before Sep 8) |
| York Pond | 1,519 ft | May 23 (1 in 10 after Jun 6) | Sep 22 (before Sep 9) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.