Basalt, ID 83236 Frost Dates
When can you plant in Basalt, ID?
Typically, the last spring freeze lands around 05/05, roughly 250 days out. The first fall frost typically arrives around 10/03, about 149 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 Basalt, not a forecast for this year.
What to do before the first frost
About 5 weeks of growing season left in Basalt before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/05 is the middle of 30 years of NOAA records, not a promise. Plant by 04/23 and you're betting against frost in roughly 9 years out of 10. 05/22 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Basalt compares
At roughly 149 frost-free days, Basalt places 35,567 of 40,283 ZIP codes in this dataset. Within ID, it ranks 123 of 320.
Learn more
zone vs. frost date covers why Zone 5b and Basalt's frost date answer different questions. the frost range covers how to read the range around Basalt's dates instead of trusting one.