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Maine Frost Dates: Last and First Frost by Town

82 NOAA weather stations · 1991–2020 U.S. Climate Normals · Data updated 2026-10-29

Quick answer

Across Maine's 82 NOAA stations with regular frost, the median last spring frost is May 8 and the median first fall frost is October 2. Last frost dates range from April 21 at Woodland to June 2 at Allagash, so enter your ZIP code below for the station nearest you.

How frost dates vary across Maine

  • Elevation matters: across Maine's stations, each 1,000 ft of elevation delays the median last frost by about 13 days.
  • North vs south: stations in the northern third of the state (north of 45.3°N) reach their median last frost about 14 days later than the southern third (south of 44.4°N).
  • Safety margin: the median 10%-risk date (May 23) is about 15 days after the median last frost. Waiting until then cuts the chance of a killing frost on tender transplants from 1 in 2 to 1 in 10.

Frost dates at Maine's major weather stations

These National Weather Service stations, mostly at airports, have the longest and most complete records in the state.
Augusta State Airport350Apr 27May 7Oct 16172
Bangor Intl Airport148May 4May 17Oct 4152
Brunswick NAS70May 2May 14Oct 10160
Caribou Municipal Airport624May 7May 24Oct 1143
Frenchville Aroostook Airport988May 6May 21Oct 2147
Fryeburg E Slopes Airport445May 17Jun 1Sep 25128
Greenville Maine Forestry Svc1,037May 7May 20Oct 9153
Houlton Intl Airport476May 27Jun 10Sep 18115
Limestone 4 NNW737May 16Jun 1Sep 24129
Millinocket Municipal Airport406May 8May 24Oct 1143
Old Town 2 W127May 13May 28Sep 28137
Portland Intl Jetport45Apr 26May 7Oct 15170
Wiscasset Airport68May 8May 20Oct 7151

All 82 stations in Maine

Last frost and first frost are medians: a 50% chance of a 32°F night after (spring) or before (fall) that date. 10% risk is the spring date with only a 1-in-10 chance of a later frost. Click a column to sort.
Acadia National Park470Apr 27May 8Oct 22177
Allagash596Jun 2Jun 21Sep 15102
Andover 2822May 19Jun 1Sep 25129
Augusta State Airport350Apr 27May 7Oct 16172
Bangor Intl Airport148May 4May 17Oct 4152
Barnard545May 12May 26Oct 1141
Bath25May 10May 23Oct 6149
Belfast20May 7May 21Oct 5151
Bethel 6 SSE790May 6May 19Oct 2147
Brassua Dam1,069May 23Jun 4Sep 29128
Bridgewater420May 25Jun 7Sep 18115
Bridgton 3 NW508May 5May 17Oct 5151
Brunswick NAS70May 2May 14Oct 10160
Cape Neddick152May 1May 14Oct 14165
Caribou Municipal Airport624May 7May 24Oct 1143
Clayton Lake1,000May 30Jun 12Sep 13106
Corinna297May 8May 23Oct 3148
Danforth475May 25Jun 8Sep 24119
Dover-foxcroft Wwtp370May 15May 28Sep 28134
Durham140May 15May 28Oct 2139
E Sangerville635May 6May 20Oct 7153
E Surry105May 8May 23Oct 9152
East Hiram528May 12May 25Oct 1140
Eastport85Apr 29May 11Oct 25178
Eustis1,260May 24Jun 6Sep 21118
Farmington405May 16Jun 1Sep 26130
Fort Kent610May 23Jun 6Sep 24121
Frenchville Aroostook Airport988May 6May 21Oct 2147
Fryeburg E Slopes Airport445May 17Jun 1Sep 25128
Gardiner133May 1May 14Oct 11163
Grand Lake Stream290May 4May 18Oct 10157
Gray378Apr 28May 10Oct 19172
Greenville Maine Forestry Svc1,037May 7May 20Oct 9153
Harmony320May 11May 25Oct 1141
Hartford705May 6May 21Oct 3148
Hollis304May 14May 28Sep 30136
Houlton 5N390May 19Jun 2Sep 23125
Houlton Intl Airport476May 27Jun 10Sep 18115
Jackman1,214May 26Jun 7Sep 23119
Jonesboro194May 3May 16Oct 9158
Kennebunkport20May 9May 22Oct 3146
Lewiston180Apr 25May 6Oct 19177
Limestone 4 NNW737May 16Jun 1Sep 24129
Lincoln Sanitary District/wtp190May 4May 16Oct 6153
Livermore Falls 1 E380May 11May 24Sep 29138
Long Falls Dam1,160May 13May 27Sep 30138
Madison220May 8May 20Oct 5149
Middle Dam1,460May 19May 31Oct 1133
Millinocket360May 9May 24Oct 5147
Millinocket Municipal Airport406May 8May 24Oct 1143
Millinocket Wastewater360May 17May 31Sep 29133
Moosehead1,037May 13May 29Sep 30137
New Sharon480May 7May 22Oct 2146
Newcastle213Apr 27May 10Oct 18172
Old Town 2 W127May 13May 28Sep 28137
Orono115May 1May 14Oct 6157
Patten 2820May 13May 30Sep 30138
Pittston Farm1,100May 20Jun 3Sep 23123
Pittston Farms Nepp1,076May 21Jun 4Sep 21122
Poland570May 3May 16Oct 7157
Portland Intl Jetport45Apr 26May 7Oct 15170
Presque Isle599May 14Jun 1Sep 26131
Rangeley1,530May 23Jun 3Sep 27127
Rangeley 2 NW1,780May 23Jun 5Sep 24123
Robbinston115May 5May 18Oct 13160
Rumford 1 SSE630May 4May 17Oct 6155
Rumford 6SW630May 12May 27Sep 29139
Sanford 2 NNW289May 16May 29Sep 30136
Sebec Lake380May 16Jun 1Oct 1135
Tenants Harbor21Apr 27May 8Oct 25178
Topsfield 2620May 6May 18Oct 8155
Turner565May 1May 13Oct 10162
Van Buren 2456May 23Jun 5Sep 26125
Vanceboro No 2420May 13May 28Oct 1139
W Rockport 1 NNW361Apr 27May 9Oct 19175
Waterville Trtmt Plt73May 2May 14Oct 10159
Wesley410May 2May 12Oct 15164
West Buxton 2 NNW220May 7May 18Oct 4148
Westport Island90Apr 28May 9Oct 21175
Windham 2NW443Apr 30May 12Oct 20172
Wiscasset Airport68May 8May 20Oct 7151
Woodland123Apr 21May 2Oct 26185

Frequently asked questions

When is the last frost in Maine?

The median last spring frost (32°F) across Maine's NOAA weather stations is May 8, based on 1991–2020 climate normals. It ranges from April 21 at Woodland to June 2 at Allagash. For a safer planting date, use the 10%-risk date; the state median for that is May 23.

When is the first frost in Maine?

The median first fall frost across Maine's stations is October 2. The earliest median first frost is September 13 at Clayton Lake, and the latest is October 26 at Woodland.

How long is the growing season in Maine?

The median frost-free season is 147 days across Maine's stations, from 102 days at Allagash to 185 days at Woodland.

When should I plant tomatoes in Maine?

Plant tomatoes outdoors after your local last frost, ideally after the 10%-risk date when nights stay above 50°F. At a typical Maine station that means starting seeds indoors 6–8 weeks before May 8 and transplanting from about May 23. Check your ZIP code, because dates vary by weeks across the state.

How to use these dates

Frost dates are 30-year averages from NOAA, not forecasts. Use them to plan seed starting and planting, then watch the 10-day forecast as the date approaches. Cold air settles in valleys and low spots, so a garden at the bottom of a slope can frost a week or more later in spring than the nearest station shows.

Ready to plan? The planting calendar by ZIP code turns these dates into start-indoors, transplant and sowing dates for 30 crops.

Sources and method

Dates are the 32°F freeze probabilities published in the NOAA NCEI 1991–2020 U.S. Climate Normals for each station. Station names are NOAA's, lightly expanded for readability. See the methodology or download the full table.

Frost dates in other states