New Plymouth, ID 83655 Frost Dates
83655, near New Plymouth, ID: the frost window
Typically, the last spring freeze lands around 04/21, roughly 236 days out. Fall's first freeze usually shows up around 10/14, roughly 176 days after the last spring frost.
New Plymouth sits in USDA Zone 7a (0 to 5°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
New Plymouth's growing season runs out in roughly 7 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around New Plymouth's last frost
04/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/08 and only about 1 year in 10 sees frost after that.
New Plymouth against the rest of the dataset
At roughly 176 frost-free days, New Plymouth places 26,505 of 40,283 ZIP codes in this dataset. Within ID, it ranks 51 of 320.
Learn more
Two guides worth reading on 83655: local microclimates, on what one yard in New Plymouth can differ from the 83655 normal, and zone vs. frost date, on why Zone 7a and New Plymouth's frost date answer different questions.