Maryland frost dates: M
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Madison | Mar 29 | Nov 15 | 231 d | 8a |
| Manchester | Apr 19 | Oct 25 | 189 d | 7a |
| Manokin | Apr 3 | Nov 7 | 218 d | 7b |
| Marbury | Mar 28 | Nov 8 | 225 d | 7b |
| Mardela Springs | Apr 8 | Nov 4 | 210 d | 7b |
| Marion Station | Mar 31 | Nov 11 | 225 d | 8a |
| Marriottsville | Apr 2 | Nov 7 | 219 d | 7b |
| Marydel | Apr 4 | Nov 4 | 214 d | 7b |
| Maryland Line | Apr 19 | Oct 25 | 189 d | 7a |
| Massey | Apr 3 | Nov 5 | 216 d | 7b |
| Maugansville | Apr 7 | Nov 4 | 211 d | 7a |
| Mayo | Mar 23 | Nov 20 | 242 d | 8a |
| Mc Henry | May 9 | Oct 11 | 155 d | 6a |
| Mcdaniel | Apr 1 | Nov 7 | 220 d | 8a |
| Mechanicsville | Apr 17 | Oct 27 | 193 d | 7b |
| Middle River | Mar 24 | Nov 21 | 242 d | 8a |
| Middletown | Apr 2 | Nov 6 | 218 d | 7a |
| Midland | Apr 29 | Oct 18 | 172 d | 6b |
| Midlothian | Apr 29 | Oct 18 | 172 d | 6b |
| Millersville | Apr 10 | Oct 31 | 204 d | 7b |
| Millington | Apr 3 | Nov 5 | 216 d | 7b |
| Monkton | Apr 2 | Nov 7 | 219 d | 7a |
| Monrovia | Apr 14 | Oct 29 | 198 d | 7a |
| Montgomery Village | Apr 1 | Nov 6 | 219 d | 7b |
| Morganza | Apr 17 | Oct 27 | 193 d | 7b |
| Mount Airy | Apr 14 | Oct 29 | 198 d | 7a |
| Mount Rainier | Mar 29 | Nov 8 | 224 d | 7b |
| Mount Savage | Apr 29 | Oct 18 | 172 d | 6b |
| Mount Victoria | Apr 17 | Oct 27 | 193 d | 7b |
| Myersville | Apr 14 | Oct 30 | 199 d | 7a |