Bloomington, ID 83233 Frost Dates
When can you plant in Bloomington, ID?
Typically, the last spring freeze lands around 06/17, roughly 293 days out. The first fall frost typically arrives around 09/03, about 77 frost-free days later.
The USDA Plant Hardiness Zone Map puts Bloomington in Zone 5a (-20 to -15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 1 week of growing season left in Bloomington before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 06/17 isn't a guarantee
06/17 is the middle of 30 years of NOAA records, not a promise. Plant by 05/31 and you're betting against frost in roughly 9 years out of 10. 07/04 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Bloomington compares
Bloomington's growing season runs about 77 days, ranking 40,083 of 40,283 US ZIP codes measured here, longest to shortest. Within ID, it ranks 297 of 320.
Learn more
zone vs. frost date covers why Zone 5a and Bloomington's frost date answer different questions. the frost range covers how to read the range around Bloomington's dates instead of trusting one.