Frost Dates for 83536 — Kamiah, Idaho

Half of springs at Kamiah, ID see their last 32°F night by April 29; only one in ten is past it by April 9, and one in ten still has one after May 12. Planting tender crops after May 3 leaves a 30% risk of a frost on them, after May 7 20%, and after May 12 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 97% of the 67 Idaho stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 5 in half of years, as early as September 22 one year in ten, and holds off past October 24 one year in ten. A hard freeze of 28°F follows 15 days later, around October 20; in spring the one-in-ten date for 28°F is April 29, 13 days before the 32°F one. The freeze-free season lasts 163 days in a typical year, longer than at 72% of the 67 Idaho stations; it reaches 186 days one year in ten and falls short of 139 one year in ten. On average 120 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 12 days longer, to about May 11, and return around September 25. Severe cold of 16°F or below comes in 99% of winters, usually between December 4 and February 6.

August is the warmest month at Kamiah, ID, averaging 91°F by day and 52°F at night; December is the coldest at 36°F and 26°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 41% of years.

Warmth for growing adds up to 2,589 growing degree days a year (base 50°F), more than at 67% of the 67 Idaho stations. 31% of them (796) have built up by the end of June, and August adds the most, 663. Precipitation totals 24.1 inches a year, most in April (2.8") and least in August (0.7"); May to September bring 33% of it.

The nearest other station, Grangeville, ID, 20 miles south of Kamiah and 2,090 feet higher, has a last frost 10 days later (May 9), a first frost 2 days earlier (October 3), a season 17 days shorter.

The first measurable snow (0.1 inch or more) in Kamiah usually arrives around December 10, and the last of the season around January 28. Those are the middle dates across the winters of 1991–2020 at Kamiah, ID, 0.4 miles away: half of years saw snow earlier, half later. Snow fell in 85% of those winters. The last 32°F night of spring typically comes 91 days after the last snow.

ZIP 83536 is under a mile from Kamiah, ID, which stands at 1,210 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 83536 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.