Calais, ME 04657 Frost Dates
Calais, ME: when does the frost end?
Around 04/21 is the usual last spring frost, about 236 days away. Fall's first freeze usually shows up around 10/26, roughly 185 days after the last spring frost.
Calais sits in USDA Zone 5b (-15 to -10°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.
Stretching the season past the first frost
With roughly 8 weeks until Calais's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Calais's last frost
04/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/09 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/02 and only about 1 year in 10 sees frost after that.
Calais against the rest of the dataset
About 185 days separate Calais's last and first frost, putting it 23,165 of 40,283 ZIP codes nationally. Within ME, it ranks 2 of 456.
Learn more
Before leaning on 04657's figures: zone vs. frost date explains why Zone 5b and Calais's frost date answer different questions, while the frost range explains how to read the range around Calais's dates instead of trusting one.