Last frost dates in Massachusetts
69 NOAA weather stations in Massachusetts have thirty years of frost records. The median station sees its last 32 °F night around Apr 27; across the state that ranges from Apr 4 to May 17, so pick the station nearest you rather than a state-wide figure.
| BOSTON LOGAN INTL AP | Apr 4 | Apr 17 | Mar 25 | Nov 9 | 218 |
| CHATHAM | Apr 5 | Apr 18 | Mar 27 | Nov 15 | 221 |
| NEW BEDFORD COOP | Apr 11 | Apr 22 | Mar 30 | Nov 5 | 208 |
| WOODS HOLE GOLF CLUB | Apr 11 | Apr 24 | Mar 31 | Nov 11 | 213 |
| CHATHAM MUNI AP | Apr 13 | Apr 26 | Apr 1 | Nov 4 | 206 |
| LAWRENCE | Apr 13 | Apr 29 | Apr 1 | Oct 28 | 198 |
| NANTUCKET MEM AP | Apr 13 | Apr 27 | Apr 2 | Nov 8 | 208 |
| W HARWICH | Apr 13 | Apr 26 | Apr 2 | Nov 3 | 204 |
| PLYMOUTH-KINGSTON | Apr 15 | Apr 28 | Apr 2 | Nov 1 | 198 |
| HYANNIS | Apr 16 | Apr 30 | Apr 5 | Oct 30 | 195 |
| EDGARTOWN | Apr 17 | May 3 | Apr 4 | Nov 3 | 199 |
| BLUE HILL COOP | Apr 18 | Apr 30 | Apr 7 | Oct 26 | 190 |
| BLUE HILL | Apr 19 | May 1 | Apr 8 | Oct 24 | 187 |
| JAMAICA PLAIN | Apr 19 | May 3 | Apr 6 | Oct 23 | 185 |
| E WAREHAM | Apr 21 | May 3 | Apr 7 | Oct 24 | 186 |
| LAWRENCE MUNI AP | Apr 21 | May 1 | Apr 9 | Oct 21 | 182 |
| BROCKTON | Apr 22 | May 5 | Apr 8 | Oct 19 | 178 |
| HYANNIS BARNSTABLE MUNI AP | Apr 22 | May 5 | Apr 9 | Oct 28 | 188 |
| TAUNTON | Apr 22 | May 6 | Apr 10 | Oct 19 | 179 |
| MIDDLEBORO | Apr 23 | May 6 | Apr 12 | Oct 16 | 174 |
| NWS BOSTON/NORTON | Apr 23 | May 5 | Apr 10 | Oct 17 | 177 |
| ROCHESTER | Apr 23 | May 7 | Apr 10 | Oct 21 | 180 |
| WORCESTER RGNL AP | Apr 23 | May 5 | Apr 11 | Oct 21 | 181 |
| BEVERLY MUNI AP | Apr 24 | May 6 | Apr 11 | Oct 17 | 177 |
| HINGHAM | Apr 25 | May 8 | Apr 13 | Oct 22 | 177 |
| MARBLEHEAD | Apr 25 | May 13 | Apr 12 | Oct 20 | 176 |
| NORWOOD MEM AP | Apr 25 | May 11 | Apr 9 | Oct 9 | 167 |
| READING | Apr 25 | May 8 | Apr 13 | Oct 17 | 174 |
| SOUTHBRIDGE 3 SW | Apr 25 | May 8 | Apr 14 | Oct 13 | 168 |
| TULLY LAKE | Apr 25 | May 8 | Apr 13 | Oct 17 | 175 |
| E SANDWICH | Apr 26 | May 9 | Apr 15 | Oct 26 | 180 |
| NATICK | Apr 26 | May 9 | Apr 14 | Oct 12 | 169 |
| BEDFORD | Apr 27 | May 11 | Apr 13 | Oct 13 | 169 |
| NORTON W | Apr 27 | May 10 | Apr 14 | Oct 15 | 168 |
| WALPOLE 2 | Apr 27 | May 11 | Apr 15 | Oct 14 | 169 |
| BEDFORD HANSCOM FLD | Apr 28 | May 12 | Apr 13 | Oct 10 | 165 |
| E BRIMFIELD LAKE | Apr 28 | May 17 | Apr 14 | Oct 15 | 169 |
| WESTFIELD 3 SW | Apr 28 | May 11 | Apr 15 | Oct 17 | 171 |
| FITCHBURG MUNI AP | Apr 29 | May 13 | Apr 19 | Oct 11 | 164 |
| NEW BEDFORD MUNI AP | Apr 29 | May 15 | Apr 17 | Oct 15 | 167 |
| LOWELL | Apr 30 | May 10 | Apr 19 | Oct 10 | 164 |
| PLYMOUTH MUNI AP | Apr 30 | May 12 | Apr 19 | Oct 16 | 170 |
| WEST MEDWAY | Apr 30 | May 14 | Apr 17 | Oct 9 | 162 |
| BRIDGEWATER | May 1 | May 15 | Apr 20 | Oct 9 | 161 |
| BUFFUMVILLE LAKE | May 1 | May 13 | Apr 21 | Oct 10 | 162 |
| FITCHBURG COOP | May 1 | May 14 | Apr 19 | Oct 9 | 162 |
| GREENFIELD #3 | May 1 | May 15 | Apr 19 | Oct 11 | 162 |
| HAVERHILL | May 1 | May 14 | Apr 20 | Oct 12 | 163 |
| ASHBURNHAM | May 2 | May 16 | Apr 19 | Oct 13 | 163 |
| LEVERETT #2 | May 2 | May 16 | Apr 21 | Oct 9 | 160 |
| MAYNARD 2 | May 2 | May 16 | Apr 22 | Oct 6 | 156 |
| TAUNTON MUNI AP | May 2 | May 16 | Apr 19 | Oct 8 | 158 |
| BELCHERTOWN | May 3 | May 16 | Apr 21 | Oct 14 | 164 |
| GROVELAND | May 3 | May 17 | Apr 22 | Oct 8 | 158 |
| MIDDLETON | May 3 | May 20 | Apr 20 | Oct 9 | 157 |
| WESTFIELD BARNES MUNI AP | May 3 | May 17 | Apr 20 | Oct 8 | 158 |
| BEVERLY | May 4 | May 17 | Apr 24 | Oct 12 | 160 |
| ORANGE MUNI AP | May 4 | May 17 | Apr 23 | Oct 8 | 157 |
| AMHERST | May 5 | May 19 | Apr 23 | Oct 8 | 156 |
| ASHBURNHAM N | May 5 | May 19 | Apr 25 | Oct 7 | 152 |
| PITTSFIELD MUNI AP | May 5 | May 21 | Apr 23 | Oct 5 | 152 |
| BIRCH HILL DAM | May 6 | May 19 | Apr 25 | Oct 1 | 148 |
| LENOX DALE | May 7 | May 21 | Apr 26 | Oct 3 | 147 |
| VINEYARD HAVEN AP | May 7 | May 27 | Apr 22 | Oct 9 | 156 |
| NORTH ADAMS HARRIMAN AP | May 10 | May 25 | Apr 27 | Oct 4 | 147 |
| BARRE FALLS DAM | May 12 | May 28 | Apr 27 | Oct 1 | 141 |
| WORTHINGTON | May 13 | May 26 | Apr 29 | Oct 2 | 144 |
| ROWE 3NE | May 14 | May 26 | Apr 30 | Oct 4 | 143 |
| E HAWLEY | May 17 | May 30 | May 2 | Oct 1 | 136 |
How to read the three dates
Average is the date by which, in half of the years between 1991 and 2020, the last 32 °F night had already happened. Safe is later: only one year in ten saw a frost after it, which is the date to set out frost-tender plants such as dahlia tubers and zinnia seedlings. Early is the risky end, with a frost after it in nine years out of ten.
Every figure is for the weather station, not for your garden. A valley bottom, a north slope or a spot near a lake can run a week or two either way. Cities are warmer than the countryside around them.
Where the numbers come from
The dates are NOAA's U.S. Climate Normals for 1991 to 2020, computed by the National Centers for Environmental Information for every station with thirty years of daily minimum temperatures. ZIP codes are matched to the nearest such station within 150 km using U.S. Census Bureau ZIP Code Tabulation Area centroids. Stations that never see a frost, such as much of south Florida, report no date and are left out.