Westbrook, ME 04039 Frost Dates
Frost dates for Westbrook, ME, ZIP 04039
Around 04/28 is the usual last spring frost, about 243 days away. The first fall frost typically arrives around 10/19, about 172 frost-free days later.
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 Westbrook, not a forecast for this year.
What to do before the first frost
Zone 5b around Westbrook has about 7 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Westbrook's last frost
04/28 is the middle of 30 years of NOAA records, not a promise. Plant by 04/15 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Westbrook compares
Westbrook's growing season runs about 172 days, ranking 28,188 of 40,283 US ZIP codes measured here, longest to shortest. Within ME, it ranks 82 of 456.
Learn more
the frost range explains how to read the range around Westbrook's dates instead of trusting one, and local microclimates explains what one yard in Westbrook can differ from the 04039 normal.