Waterville, ME 04947 Frost Dates
04947, near Waterville, ME: the frost window
The last spring frost here typically falls around 05/13, about 258 days from today. Fall's first freeze usually shows up around 09/30, roughly 138 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Waterville in Zone 5a (-20 to -15°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
Waterville's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/13 isn't a guarantee
05/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/30 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/27 and only about 1 year in 10 sees frost after that.
Waterville against the rest of the dataset
Waterville's growing season runs about 138 days, ranking 37,357 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 364 of 456.
Learn more
Two guides worth reading on 04947: local microclimates, on what one yard in Waterville can differ from the 04947 normal, and zone vs. frost date, on why Zone 5a and Waterville's frost date answer different questions.