Boise City, ID 83716 Frost Dates
When can you plant in Boise City, ID?
Typically, the last spring freeze lands around 04/28, roughly 243 days out. The first fall frost typically arrives around 10/14, about 169 frost-free days later.
Zone 6b (-5 to 0°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 Boise City, not a forecast for this year.
What to do before the first frost
About 7 weeks of growing season left in Boise City before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/28 isn't a guarantee
04/28 is the middle of 30 years of NOAA records, not a promise. Plant by 04/11 and you're betting against frost in roughly 9 years out of 10. 05/16 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Boise City compares
Boise City's growing season runs about 169 days, ranking 29,281 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 57 of 320.
Learn more
local microclimates covers what one yard in Boise City can differ from the 83716 normal. zone vs. frost date covers why Zone 6b and Boise City's frost date answer different questions.