Frost dates for Boise

◇ Station-based · 89/100 confidence

Last spring frost · safe

May 15

~10% frost risk · typical May 2

First fall frost · safe

Sep 27

~10% frost risk · typical Oct 17

Frost-free days

168

May 2 → Oct 17

Climate zone

Cold semi-arid

Köppen BSk

The growing year

Frost-bounded season with crops mapped onto the 12-month axis.

Frost risk Growing Harvest

JAN

FEB

MAR

APR

MAY

JUN

JUL

AUG

SEP

OCT

NOV

DEC

FROST

GROWING SEASON — 168 DAYS

MAY 2

OCT 17