Portland, ME 04107 Frost Dates
When can you plant in Portland, ME?
Around 04/26 is the usual last spring frost, about 241 days away. The first fall frost typically arrives around 10/15, about 170 frost-free days later.
Portland sits in USDA Zone 6a (-10 to -5°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 7 weeks of growing season left in Portland before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Portland's last frost
04/26 is the middle of 30 years of NOAA records, not a promise. Plant by 04/16 and you're betting against frost in roughly 9 years out of 10. 05/07 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Portland compares
At roughly 170 frost-free days, Portland places 28,885 of 40,283 ZIP codes in this dataset. Within ME, it ranks 119 of 456.
Learn more
the frost range covers how to read the range around Portland's dates instead of trusting one. local microclimates covers what one yard in Portland can differ from the 04107 normal.