Westbrook, ME 04041 Frost Dates
Westbrook, ME: when does the frost end?
Around 05/17 is the usual last spring frost, about 262 days away. Fall's first freeze usually shows up around 09/25, roughly 128 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 Westbrook, not a forecast for this year.
Stretching the season past the first frost
With roughly 4 weeks until Westbrook's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/17 isn't a guarantee
05/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/02 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
Westbrook against the rest of the dataset
At roughly 128 frost-free days, Westbrook places 38,523 of 40,283 ZIP codes in this dataset. Within ME, it ranks 431 of 456.
Learn more
Before leaning on 04041's figures: the frost range explains how to read the range around Westbrook's dates instead of trusting one, while local microclimates explains what one yard in Westbrook can differ from the 04041 normal.