Waterville, ME 04912 Frost Dates
Waterville, ME: when does the frost end?
Typically, the last spring freeze lands around 05/11, roughly 256 days out. Fall's first freeze usually shows up around 10/01, roughly 141 days after the last spring frost.
Zone 5a (-20 to -15°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 Waterville, not a forecast for this year.
Stretching the season past the first frost
With roughly 5 weeks until Waterville's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Waterville's last frost
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
About 141 days separate Waterville's last and first frost, putting it 36,870 of 40,283 ZIP codes nationally. Within ME, it ranks 353 of 456.
Learn more
Before leaning on 04912's figures: zone vs. frost date explains why Zone 5a and Waterville's frost date answer different questions, while the frost range explains how to read the range around Waterville's dates instead of trusting one.