| City | Population | Last spring frost | First fall frost | Growing season | Zone |
|---|---|---|---|---|---|
| Manchester | 116,818 | Apr 30 | Oct 11 | 164 days | 6a |
| Nashua | 92,435 | Apr 29 | Oct 8 | 162 days | 6a |
| Concord | 44,597 | May 8 | Oct 3 | 146 days | 5b |
| Dover | 34,623 | May 3 | Oct 10 | 158 days | 6a |
| Rochester | 33,716 | Apr 30 | Oct 9 | 161 days | 6a |
| Keene | 23,072 | May 14 | Oct 1 | 138 days | 5b |
| Portsmouth | 23,028 | May 4 | Oct 8 | 157 days | 6a |
| Laconia | 17,246 | Apr 30 | Oct 18 | 170 days | 5b |
| Lebanon | 15,481 | May 9 | Oct 6 | 148 days | 5a |
| Claremont | 13,032 | May 14 | Oct 1 | 140 days | 5b |
| Somersworth | 12,171 | Apr 30 | Oct 9 | 161 days | 6a |
| Berlin | 9,502 | May 23 | Sep 22 | 122 days | 4b |
| Franklin | 8,839 | May 7 | Oct 3 | 148 days | 5b |
Growing zones in New Hampshire · Frost dates in other states