Spirit Lake, ID 83804 Frost Dates
Spirit Lake, ID: when does the frost end?
Typically, the last spring freeze lands around 05/12, roughly 257 days out. Fall's first freeze usually shows up around 09/21, roughly 130 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Spirit Lake in Zone 6b (-5 to 0°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 3 weeks until Spirit Lake's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/12 isn't a guarantee
05/12 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/29 and only about 1 year in 10 sees frost after that.
Spirit Lake against the rest of the dataset
At roughly 130 frost-free days, Spirit Lake places 38,376 of 40,283 ZIP codes in this dataset. Within ID, it ranks 180 of 320.
Learn more
Before leaning on 83804's figures: the frost range explains how to read the range around Spirit Lake's dates instead of trusting one, while local microclimates explains what one yard in Spirit Lake can differ from the 83804 normal.