Maine Frost Dates
Across Maine's 23 cities and towns, the average last spring frost runs from April 25 in Auburn to May 16 in Sanford. Average last frost elsewhere: Portland Apr 26, Bangor May 4 and Presque Isle May 14.
Frost dates for every city and town in Maine
Dates are for 32°F at the NOAA station nearest the ZIP code at each Maine town's center. "Safer date" is when only 1 year in 10 still gets a frost, a good target for tomatoes and peppers.
| City | Average last frost | Safer date | Average first frost | Frost-free days |
|---|---|---|---|---|
| Auburn | Apr 25 | May 6 | Oct 19 | 177 |
| Augusta | Apr 27 | May 7 | Oct 16 | 172 |
| Bangor | May 4 | May 17 | Oct 4 | 153 |
| Bath | May 10 | May 23 | Oct 6 | 149 |
| Belfast | May 7 | May 21 | Oct 5 | 151 |
| Biddeford | May 9 | May 22 | Oct 3 | 147 |
| Brewer | May 4 | May 17 | Oct 4 | 153 |
| Calais | May 5 | May 18 | Oct 13 | 161 |
| Caribou | May 7 | May 24 | Oct 1 | 147 |
| Eastport | Apr 29 | May 11 | Oct 25 | 179 |
| Ellsworth | May 8 | May 23 | Oct 9 | 154 |
| Gardiner | May 1 | May 14 | Oct 11 | 163 |
| Hallowell | Apr 27 | May 7 | Oct 16 | 172 |
| Lewiston | Apr 25 | May 6 | Oct 19 | 177 |
| Old Town | May 1 | May 14 | Oct 6 | 158 |
| Portland | Apr 26 | May 7 | Oct 15 | 172 |
| Presque Isle | May 14 | Jun 1 | Sep 26 | 135 |
| Rockland | Apr 27 | May 9 | Oct 19 | 175 |
| Saco | Apr 26 | May 7 | Oct 15 | 172 |
| Sanford | May 16 | May 29 | Sep 30 | 137 |
| South Portland | Apr 26 | May 7 | Oct 15 | 172 |
| Waterville | May 2 | May 14 | Oct 10 | 161 |
| Westbrook | Apr 26 | May 7 | Oct 15 | 172 |
Source: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020. City centers from the US Census Bureau. Click a city for its nearest station and, where it has frost dates, hard-freeze dates and a vegetable planting calendar. See how we calculate.
Frequently asked questions
When is the last frost in Portland, ME?
The average last spring frost in Portland is April 26, and only 1 year in 10 has a frost after May 7. The average first fall frost is October 15. These come from NOAA's 1991–2020 records at the Portland INTL Jetport station.
When should I plant tomatoes in Maine?
UNH Extension times tomato transplants for 1 to 2 weeks after the average last frost. In Portland that's about May 3 to May 10. Look up your ZIP code for your own dates and a full vegetable planting calendar.
More for Maine: Maine climate zones (insulation) · Maine planting zones · Frost line depth by state