Lewiston, ME 04280 Frost Dates
04280, near Lewiston, ME: the frost window
Typically, the last spring freeze lands around 04/25, roughly 240 days out. Fall's first freeze usually shows up around 10/19, roughly 177 days after the last spring frost.
Zone 5b (-15 to -10°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Lewiston, not a forecast for this year.
Stretching the season past the first frost
Lewiston's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 04/25 isn't a guarantee
04/25 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/11 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/06 and only about 1 year in 10 sees frost after that.
Lewiston against the rest of the dataset
Lewiston's growing season runs about 177 days, ranking 26,018 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 23 of 456.
Learn more
Two guides worth reading on 04280: the frost range, on how to read the range around Lewiston's dates instead of trusting one, and local microclimates, on what one yard in Lewiston can differ from the 04280 normal.