Connecticut frost dates: S
| City | Last frost | First frost | Season | Zone |
|---|---|---|---|---|
| Salem | Apr 14 | Oct 24 | 193 d | 6b |
| Salisbury | May 11 | Oct 4 | 146 d | 6a |
| Sandy Hook | Apr 20 | Oct 20 | 183 d | 6b |
| Scotland | Apr 30 | Oct 15 | 168 d | 6b |
| Seymour | Apr 25 | Oct 17 | 175 d | 6b |
| Sharon | May 11 | Oct 4 | 146 d | 6a |
| Shelton | Apr 25 | Oct 17 | 175 d | 6b |
| Sherman | Apr 28 | Oct 16 | 171 d | 6b |
| Simsbury | Apr 21 | Oct 16 | 178 d | 6b |
| Somers | May 7 | Oct 12 | 158 d | 6b |
| Somersville | Apr 21 | Oct 16 | 178 d | 6b |
| South Britain | Apr 20 | Oct 20 | 183 d | 6b |
| South Glastonbury | Apr 17 | Oct 26 | 192 d | 6b |
| South Kent | May 4 | Oct 7 | 156 d | 6a |
| South Lyme | Apr 16 | Oct 28 | 195 d | 7a |
| South Willington | Apr 19 | Oct 22 | 186 d | 6b |
| South Windham | Apr 28 | Oct 13 | 168 d | 6b |
| South Windsor | Apr 17 | Oct 26 | 192 d | 6b |
| South Woodstock | May 1 | Oct 9 | 161 d | 6b |
| Southbury | Apr 25 | Oct 17 | 175 d | 6b |
| Southington | Apr 26 | Oct 16 | 173 d | 6b |
| Southport | Apr 5 | Nov 6 | 215 d | 7a |
| Stafford | May 7 | Oct 12 | 158 d | 6a |
| Stafford Springs | May 7 | Oct 12 | 158 d | 6b |
| Staffordville | May 7 | Oct 12 | 158 d | 6a |
| Stamford | Apr 17 | Oct 23 | 189 d | 7a |
| Sterling | Apr 25 | Oct 19 | 177 d | 6b |
| Stevenson | Apr 25 | Oct 17 | 175 d | 6b |
| Stonington | Apr 11 | Oct 31 | 203 d | 7a |
| Storrs Mansfield | Apr 19 | Oct 22 | 186 d | 6b |
| Stratford | Apr 5 | Nov 6 | 215 d | 7a |
| Suffield | Apr 21 | Oct 16 | 178 d | 6b |