Frost dates in Maine
Across Maine's 82 NOAA stations with a frost every year, the typical last spring frost ranges from April 21 at Woodland (120 feet above sea level) to June 2 at Allagash (600 feet above sea level). The middle station's date is May 8.
Look up your ZIP code
Last frost across Maine
The frost-free season runs from 102 days at Allagash to 185 days at Woodland.
These are typical dates: in half of springs the last frost comes later. Each place's page, and each ZIP code lookup, also gives the late-year date, after which only 1 spring in 10 has a frost. That's the safer date for tender plants.
Frost dates for Maine's larger places
| Place | Last spring frost | First fall frost | Season | Zone |
|---|---|---|---|---|
| Bangor | May 4 | October 4 | 152 days | 5a |
| Lewiston | April 25 | October 19 | 177 days | 5b |
| Portland | April 26 | October 15 | 170 days | 6a |
Typical (1-in-2) dates. Each place's page has the early and late years, a planting calendar and a printable planner. Zones are for the ZIP code nearest each place's center.
Hardiness zones in Maine
Maine's 479 ZIP codes in the USDA list fall in zones 3b to 7a: 3b (under 1 percent), 4a (5 percent), 4b (6 percent), 5a (32 percent), 5b (31 percent), 6a (23 percent), 6b (2 percent) and 7a (under 1 percent). Compared with the 2012 map, 58 percent of them moved to a warmer half zone (17 by a full zone or more), 41 percent stayed the same and 6 moved to a colder one.
A hardiness zone is about the coldest night of winter, which decides which shrubs, trees and perennials survive. Frost dates are about spring and fall, which decide when to plant. You need both. Read more about what the zones mean and what changed in 2023.
Every NOAA station in Maine
All 82 stations in Maine with frost statistics in NOAA's 1991 to 2020 normals, from A to Z. Station names are usually a town, an airport, or a distance and direction from a town. Find one near you and at a similar elevation.
| Station | Elevation (feet) | Last spring frost | First fall frost | Season (days) |
|---|---|---|---|---|
| Acadia NP | 470 | April 27 | October 22 | 177 |
| Allagash | 600 | June 2 | September 15 | 102 |
| Andover 2 | 820 | May 19 | September 25 | 129 |
| Augusta State Airport | 350 | April 27 | October 16 | 172 |
| Bangor International Airport | 150 | May 4 | October 4 | 152 |
| Barnard | 540 | May 12 | October 1 | 141 |
| Bath | 30 | May 10 | October 6 | 149 |
| Belfast | 20 | May 7 | October 5 | 151 |
| Bethel 6 SSE | 790 | May 6 | October 2 | 147 |
| Brassua Dam | 1,070 | May 23 | September 29 | 128 |
| Bridgewater | 420 | May 25 | September 18 | 115 |
| Bridgton 3 NW | 510 | May 5 | October 5 | 151 |
| Brunswick NAS | 70 | May 2 | October 10 | 160 |
| Cape Neddick | 150 | May 1 | October 14 | 165 |
| Caribou Municipal Airport | 620 | May 7 | October 1 | 143 |
| Clayton Lake | 1,000 | May 30 | September 13 | 106 |
| Corinna | 300 | May 8 | October 3 | 148 |
| Danforth | 480 | May 25 | September 24 | 119 |
| Dover-Foxcroft WWTP | 370 | May 15 | September 28 | 134 |
| Durham | 140 | May 15 | October 2 | 139 |
| E Sangerville | 640 | May 6 | October 7 | 153 |
| E Surry | 100 | May 8 | October 9 | 152 |
| East Hiram | 530 | May 12 | October 1 | 140 |
| Eastport | 90 | April 29 | October 25 | 178 |
| Eustis | 1,260 | May 24 | September 21 | 118 |
| Farmington | 400 | May 16 | September 26 | 130 |
| Fort Kent | 610 | May 23 | September 24 | 121 |
| Frenchville Aroostook Airport | 990 | May 6 | October 2 | 147 |
| Fryeburg E Slopes Airport | 450 | May 17 | September 25 | 128 |
| Gardiner | 130 | May 1 | October 11 | 163 |
| Grand Lake Stream | 290 | May 4 | October 10 | 157 |
| Gray | 380 | April 28 | October 19 | 172 |
| Greenville Maine Forestry Service | 1,040 | May 7 | October 9 | 153 |
| Harmony | 320 | May 11 | October 1 | 141 |
| Hartford | 710 | May 6 | October 3 | 148 |
| Hollis | 310 | May 14 | September 30 | 136 |
| Houlton 5 N | 390 | May 19 | September 23 | 125 |
| Houlton International Airport | 480 | May 27 | September 18 | 115 |
| Jackman | 1,210 | May 26 | September 23 | 119 |
| Jonesboro | 190 | May 3 | October 9 | 158 |
| Kennebunkport | 20 | May 9 | October 3 | 146 |
| Lewiston | 180 | April 25 | October 19 | 177 |
| Limestone 4 NNW | 740 | May 16 | September 24 | 129 |
| Lincoln Sanitary District/wtp | 190 | May 4 | October 6 | 153 |
| Livermore Falls 1 E | 380 | May 11 | September 29 | 138 |
| Long Falls Dam | 1,160 | May 13 | September 30 | 138 |
| Madison | 220 | May 8 | October 5 | 149 |
| Middle Dam | 1,460 | May 19 | October 1 | 133 |
| Millinocket | 360 | May 9 | October 5 | 147 |
| Millinocket Municipal Airport | 410 | May 8 | October 1 | 143 |
| Millinocket Wastewater | 360 | May 17 | September 29 | 133 |
| Moosehead | 1,040 | May 13 | September 30 | 137 |
| New Sharon | 480 | May 7 | October 2 | 146 |
| Newcastle | 210 | April 27 | October 18 | 172 |
| Old Town 2 W | 130 | May 13 | September 28 | 137 |
| Orono | 110 | May 1 | October 6 | 157 |
| Patten 2 | 820 | May 13 | September 30 | 138 |
| Pittston Farm | 1,100 | May 20 | September 23 | 123 |
| Pittston Farms Nepp | 1,080 | May 21 | September 21 | 122 |
| Poland | 570 | May 3 | October 7 | 157 |
| Portland International Jetport | 50 | April 26 | October 15 | 170 |
| Presque Isle | 600 | May 14 | September 26 | 131 |
| Rangeley | 1,530 | May 23 | September 27 | 127 |
| Rangeley 2 NW | 1,780 | May 23 | September 24 | 123 |
| Robbinston | 110 | May 5 | October 13 | 160 |
| Rumford 1 SSE | 630 | May 4 | October 6 | 155 |
| Rumford 6 SW | 630 | May 12 | September 29 | 139 |
| Sanford 2 NNW | 290 | May 16 | September 30 | 136 |
| Sebec Lake | 380 | May 16 | October 1 | 135 |
| Tenants Harbor | 20 | April 27 | October 25 | 178 |
| Topsfield 2 | 620 | May 6 | October 8 | 155 |
| Turner | 560 | May 1 | October 10 | 162 |
| Van Buren 2 | 460 | May 23 | September 26 | 125 |
| Vanceboro No 2 | 420 | May 13 | October 1 | 139 |
| W Rockport 1 NNW | 360 | April 27 | October 19 | 175 |
| Waterville Treatment Plant | 70 | May 2 | October 10 | 159 |
| Wesley | 410 | May 2 | October 15 | 164 |
| West Buxton 2 NNW | 220 | May 7 | October 4 | 148 |
| Westport Island | 90 | April 28 | October 21 | 175 |
| Windham 2 NW | 440 | April 30 | October 20 | 172 |
| Wiscasset Airport | 70 | May 8 | October 7 | 151 |
| Woodland | 120 | April 21 | October 26 | 185 |
Typical (1-in-2) dates at 32°F. For the early and late years, and a planting calendar built from your own dates, look up your ZIP code.