Calais, ME 04619 Frost Dates
04619, near Calais, ME: the frost window
The last spring frost here typically falls around 04/21, about 236 days from today. Fall's first freeze usually shows up around 10/26, roughly 185 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Calais in Zone 5b (-15 to -10°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
Calais's growing season runs out in roughly 8 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
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
Calais's growing season runs about 185 days, ranking 23,164 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 1 of 456.
Learn more
Two guides worth reading on 04619: zone vs. frost date, on why Zone 5b and Calais's frost date answer different questions, and the frost range, on how to read the range around Calais's dates instead of trusting one.