| City | Population | Last spring frost | First fall frost | Growing season | Zone |
|---|---|---|---|---|---|
| Baltimore | 569,997 | Mar 24 | Nov 21 | 244 days | 8a |
| Frederick | 92,059 | Apr 2 | Nov 6 | 218 days | 7b |
| Gaithersburg | 71,113 | Apr 1 | Nov 6 | 219 days | 7b |
| Rockville | 67,563 | Apr 1 | Nov 6 | 219 days | 7b |
| Bowie | 58,383 | Apr 22 | Oct 22 | 183 days | 7a |
| Hagerstown | 44,228 | Apr 11 | Oct 28 | 199 days | 7a |
| Annapolis | 40,634 | Mar 27 | Nov 13 | 234 days | 8a |
| College Park | 35,418 | Apr 10 | Nov 1 | 202 days | 7b |
| Salisbury | 33,845 | Apr 3 | Nov 7 | 217 days | 7b |
| Laurel | 30,254 | Apr 5 | Nov 9 | 218 days | 7b |
| Greenbelt | 24,948 | Apr 10 | Nov 1 | 202 days | 7b |
| Hyattsville | 21,158 | Mar 29 | Nov 8 | 224 days | 7b |
| Westminster | 20,589 | Apr 24 | Oct 20 | 177 days | 7a |
| Cumberland | 18,799 | Apr 15 | Oct 24 | 190 days | 7a |
| Aberdeen | 18,374 | Apr 10 | Oct 30 | 201 days | 7b |
| Easton | 17,293 | Apr 1 | Nov 7 | 220 days | 8a |
| Takoma Park | 17,260 | Mar 29 | Nov 8 | 224 days | 7b |
| Elkton | 16,670 | Apr 7 | Nov 2 | 208 days | 7b |
| Havre de Grace | 15,630 | Apr 10 | Oct 30 | 201 days | 7b |
| New Carrollton | 13,644 | Apr 22 | Oct 22 | 183 days | 7b |
| Cambridge | 13,457 | Apr 1 | Nov 7 | 220 days | 8a |
| La Plata | 12,137 | Apr 17 | Oct 27 | 195 days | 7b |
| Bel Air | 10,507 | Apr 10 | Oct 30 | 201 days | 7b |
| Mount Airy | 9,857 | Apr 14 | Oct 29 | 196 days | 7a |
| Bladensburg | 9,671 | Mar 29 | Nov 8 | 224 days | 7b |
| Brunswick | 9,380 | Apr 26 | Oct 18 | 175 days | 7a |
| Mount Rainier | 8,307 | Mar 29 | Nov 8 | 224 days | 7b |
| Taneytown | 8,259 | Apr 22 | Oct 20 | 179 days | 7a |
| Riverdale Park | 7,343 | Mar 29 | Nov 8 | 224 days | 7b |
| Frostburg | 6,979 | Apr 29 | Oct 18 | 171 days | 6b |
| Ocean City | 6,840 | Apr 7 | Nov 2 | 209 days | 8a |
| Walkersville | 6,501 | Apr 2 | Nov 6 | 218 days | 7a |
| Chesapeake Beach | 6,466 | Apr 9 | Oct 29 | 203 days | 8a |
| Glenarden | 6,422 | Apr 22 | Oct 22 | 183 days | 7b |
| Thurmont | 6,337 | Apr 14 | Oct 30 | 197 days | 7a |
| Hampstead | 6,281 | Apr 19 | Oct 25 | 188 days | 7a |
| Cheverly | 6,164 | Mar 29 | Nov 8 | 224 days | 7b |
| Fruitland | 6,007 | Apr 3 | Nov 7 | 217 days | 7b |
| Poolesville | 5,942 | Apr 13 | Oct 26 | 195 days | 7b |
| District Heights | 5,938 | Mar 29 | Nov 8 | 224 days | 7b |
| Chestertown | 5,658 | Apr 3 | Nov 5 | 217 days | 7b |
| Manchester | 5,426 | Apr 19 | Oct 25 | 188 days | 7a |
| Berlin | 5,335 | Apr 7 | Nov 2 | 209 days | 7b |
| Denton | 5,075 | Apr 11 | Oct 30 | 200 days | 7b |
| Middletown | 5,056 | Apr 2 | Nov 6 | 218 days | 7a |
| Leonardtown | 5,033 | Mar 22 | Nov 26 | 248 days | 7b |