Maine frost dates
The typical last spring frost ranges from Apr 25 in Lewiston to May 9 in Kennebunkport.
5 of the 5 Maine cities listed have typical frost dates. The longest frost-free season is 177 days in Bar Harbor; the shortest is 146 days in Kennebunkport. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Bangor | May 4 | May 17 | Oct 4 | Sep 23 | Apr 23 / Oct 17 | 152 days |
| Bar Harbor | Apr 27 | May 8 | Oct 22 | Oct 6 | Apr 15 / Nov 2 | 177 days |
| Kennebunkport | May 9 | May 22 | Oct 3 | Sep 20 | Apr 29 / Oct 15 | 146 days |
| Lewiston | Apr 25 | May 6 | Oct 19 | Oct 5 | Apr 11 / Nov 1 | 177 days |
| Portland | Apr 26 | May 7 | Oct 15 | Oct 2 | Apr 14 / Oct 27 | 170 days |
Reading the table: Bar Harbor
In Bar Harbor, the last spring frost typically comes around Apr 27: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 8, 11 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Oct 22, and in 1 year in 10 before Oct 6. Hard freezes (28°F) usually end earlier in spring and start later in fall: around Apr 15 and Nov 2 in Bar Harbor.
Frost dates at more Maine weather stations
NOAA stations across Maine used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Allagash | 596 ft | Jun 2 (1 in 10 after Jun 21) | Sep 15 (before Aug 29) |
| Augusta State Airport | 350 ft | Apr 27 (1 in 10 after May 7) | Oct 16 (before Oct 2) |
| Barnard | 545 ft | May 12 (1 in 10 after May 26) | Oct 1 (before Sep 18) |
| Belfast | 20 ft | May 7 (1 in 10 after May 21) | Oct 5 (before Sep 24) |
| Bethel 6 Sse | 790 ft | May 6 (1 in 10 after May 19) | Oct 2 (before Sep 20) |
| Brassua Dam | 1,069 ft | May 23 (1 in 10 after Jun 4) | Sep 29 (before Sep 16) |
| Bridgewater | 420 ft | May 25 (1 in 10 after Jun 7) | Sep 18 (before Sep 4) |
| Bridgton 3 Nw | 508 ft | May 5 (1 in 10 after May 17) | Oct 5 (before Sep 22) |
| Brunswick NAS | 70 ft | May 2 (1 in 10 after May 14) | Oct 10 (before Sep 29) |
| Caribou Muni Airport | 624 ft | May 7 (1 in 10 after May 24) | Oct 1 (before Sep 17) |
| Clayton Lake | 1,000 ft | May 30 (1 in 10 after Jun 12) | Sep 13 (before Aug 29) |
| Corinna | 297 ft | May 8 (1 in 10 after May 23) | Oct 3 (before Sep 21) |
| Danforth | 475 ft | May 25 (1 in 10 after Jun 8) | Sep 24 (before Sep 8) |
| Dover-Foxcroft Wwtp | 370 ft | May 15 (1 in 10 after May 28) | Sep 28 (before Sep 15) |
| Durham | 140 ft | May 15 (1 in 10 after May 28) | Oct 2 (before Sep 20) |
| East Hiram | 528 ft | May 12 (1 in 10 after May 25) | Oct 1 (before Sep 19) |
| Eastport | 85 ft | Apr 29 (1 in 10 after May 11) | Oct 25 (before Oct 8) |
| Eustis | 1,260 ft | May 24 (1 in 10 after Jun 6) | Sep 21 (before Sep 6) |
| Farmington | 405 ft | May 16 (1 in 10 after Jun 1) | Sep 26 (before Sep 14) |
| Frenchville Aroostook Airport | 988 ft | May 6 (1 in 10 after May 21) | Oct 2 (before Sep 18) |
| Fryeburg E Slopes Airport | 445 ft | May 17 (1 in 10 after Jun 1) | Sep 25 (before Sep 11) |
| Ft Kent | 610 ft | May 23 (1 in 10 after Jun 6) | Sep 24 (before Sep 11) |
| Gardiner | 133 ft | May 1 (1 in 10 after May 14) | Oct 11 (before Sep 30) |
| Grand Lake Stream | 290 ft | May 4 (1 in 10 after May 18) | Oct 10 (before Oct 1) |
| Gray | 378 ft | Apr 28 (1 in 10 after May 10) | Oct 19 (before Oct 5) |
| Greenville Maine Forestry Svc | 1,037 ft | May 7 (1 in 10 after May 20) | Oct 9 (before Sep 27) |
| Hartford | 705 ft | May 6 (1 in 10 after May 21) | Oct 3 (before Sep 23) |
| Hollis | 304 ft | May 14 (1 in 10 after May 28) | Sep 30 (before Sep 16) |
| Houlton Intl Airport | 476 ft | May 27 (1 in 10 after Jun 10) | Sep 18 (before Sep 5) |
| Jackman | 1,214 ft | May 26 (1 in 10 after Jun 7) | Sep 23 (before Sep 8) |
| Jonesboro | 194 ft | May 3 (1 in 10 after May 16) | Oct 9 (before Sep 27) |
| Lincoln Sanitary District/WTP | 190 ft | May 4 (1 in 10 after May 16) | Oct 6 (before Sep 24) |
| Livermore Falls 1 E | 380 ft | May 11 (1 in 10 after May 24) | Sep 29 (before Sep 16) |
| Long Falls Dam | 1,160 ft | May 13 (1 in 10 after May 27) | Sep 30 (before Sep 15) |
| Madison | 220 ft | May 8 (1 in 10 after May 20) | Oct 5 (before Sep 24) |
| Middle Dam | 1,460 ft | May 19 (1 in 10 after May 31) | Oct 1 (before Sep 19) |
| Millinocket Muni Airport | 406 ft | May 8 (1 in 10 after May 24) | Oct 1 (before Sep 19) |
| New Sharon | 480 ft | May 7 (1 in 10 after May 22) | Oct 2 (before Sep 20) |
| Newcastle | 213 ft | Apr 27 (1 in 10 after May 10) | Oct 18 (before Oct 3) |
| Old Town 2 W | 127 ft | May 13 (1 in 10 after May 28) | Sep 28 (before Sep 16) |
| Patten 2 | 820 ft | May 13 (1 in 10 after May 30) | Sep 30 (before Sep 18) |
| Poland | 570 ft | May 3 (1 in 10 after May 16) | Oct 7 (before Sep 27) |
| Presque Isle | 599 ft | May 14 (1 in 10 after Jun 1) | Sep 26 (before Sep 10) |
| Rangeley | 1,530 ft | May 23 (1 in 10 after Jun 3) | Sep 27 (before Sep 14) |
| Rangeley 2 Nw | 1,780 ft | May 23 (1 in 10 after Jun 5) | Sep 24 (before Sep 9) |
| Robbinston | 115 ft | May 5 (1 in 10 after May 18) | Oct 13 (before Oct 1) |
| Rumford 1 Sse | 630 ft | May 4 (1 in 10 after May 17) | Oct 6 (before Sep 26) |
| Rumford 6SW | 630 ft | May 12 (1 in 10 after May 27) | Sep 29 (before Sep 15) |
| Sanford 2 Nnw | 289 ft | May 16 (1 in 10 after May 29) | Sep 30 (before Sep 18) |
| Tenants Harbor | 21 ft | Apr 27 (1 in 10 after May 8) | Oct 25 (before Oct 10) |
| Topsfield 2 | 620 ft | May 6 (1 in 10 after May 18) | Oct 8 (before Sep 28) |
| Turner | 565 ft | May 1 (1 in 10 after May 13) | Oct 10 (before Sep 29) |
| Vanceboro No 2 | 420 ft | May 13 (1 in 10 after May 28) | Oct 1 (before Sep 20) |
| W Rockport 1 Nnw | 361 ft | Apr 27 (1 in 10 after May 9) | Oct 19 (before Oct 5) |
| Waterville Trtmt Plt | 73 ft | May 2 (1 in 10 after May 14) | Oct 10 (before Sep 30) |
| Wesley | 410 ft | May 2 (1 in 10 after May 12) | Oct 15 (before Oct 1) |
| West Buxton 2 Nnw | 220 ft | May 7 (1 in 10 after May 18) | Oct 4 (before Sep 23) |
| Westport Island | 90 ft | Apr 28 (1 in 10 after May 9) | Oct 21 (before Oct 5) |
| Wiscasset Airport | 68 ft | May 8 (1 in 10 after May 20) | Oct 7 (before Sep 24) |
| Woodland | 123 ft | Apr 21 (1 in 10 after May 2) | Oct 26 (before Oct 7) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.