Waterville, ME 04943 Frost Dates
04943, near Waterville, ME: the frost window
Around 05/11 is the usual last spring frost, about 256 days away. Fall's first freeze usually shows up around 10/01, roughly 141 days after the last spring frost.
Waterville sits in USDA Zone 5a (-20 to -15°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
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 05/11 isn't a guarantee
05/11 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 05/25 and only about 1 year in 10 sees frost after that.
Waterville against the rest of the dataset
Waterville's growing season runs about 141 days, ranking 36,874 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 357 of 456.
Learn more
Two guides worth reading on 04943: zone vs. frost date, on why Zone 5a and Waterville's frost date answer different questions, and the frost range, on how to read the range around Waterville's dates instead of trusting one.