Frost Dates for 83245 — Inkom, Idaho

Half of springs at Mccammon, ID see their last 32°F night by May 23; only one in ten is past it by May 6, and one in ten still has one after June 10. Planting tender crops after May 31 leaves a 30% risk of a frost on them, after June 5 20%, and after June 10 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 42% of the 67 Idaho stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 24 in half of years, as early as September 7 one year in ten, and holds off past October 7 one year in ten. A hard freeze of 28°F follows 10 days later, around October 4; in spring the one-in-ten date for 28°F is May 21, 20 days before the 32°F one. The freeze-free season lasts 121 days in a typical year, shorter than at 78% of the 67 Idaho stations; it reaches 143 days one year in ten and falls short of 99 one year in ten. On average 179 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 19 days longer, to about June 11, and return around September 11. Severe cold of 16°F or below comes every winter, usually between November 7 and March 12.

July is the warmest month at Mccammon, ID, averaging 87°F by day and 52°F at night; January is the coldest at 32°F and 15°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 29% of years.

Warmth for growing adds up to 2,057 growing degree days a year (base 50°F), fewer than at 58% of the 67 Idaho stations. 26% of them (542) have built up by the end of June, and July adds the most, 609. Precipitation totals 15.4 inches a year, most in May (2.0") and least in July (0.6"); May to September bring 39% of it.

The nearest other station, Pocatello City, ID, 12 miles northwest of Inkom and 310 feet lower, has a last frost 21 days earlier (May 2), a first frost 17 days later (October 11), a season 40 days longer.

The first measurable snow (0.1 inch or more) in Inkom usually arrives around November 15, and the last of the season around April 6. Those are the middle dates across the winters of 1991–2020 at Mccammon, ID, 10.1 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 47 days after the last snow.

ZIP 83245 is 10 miles from Mccammon, ID, which stands at 4,770 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 83245 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°C) over 1991–2020; a zone describes winter lows, not frost dates.