Frost Dates for 83204 — Pocatello, Idaho

Half of springs at Pocatello City, ID see their last 32°F night by May 2; only one in ten is past it by April 17, and one in ten still has one after May 18. Planting tender crops after May 9 leaves a 30% risk of a frost on them, after May 13 20%, and after May 18 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 66% of the 67 Idaho stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 11 in half of years, as early as September 26 one year in ten, and holds off past October 26 one year in ten. A hard freeze of 28°F follows 13 days later, around October 24; in spring the one-in-ten date for 28°F is May 4, 14 days before the 32°F one. The freeze-free season lasts 161 days in a typical year, longer than at 70% of the 67 Idaho stations; it reaches 180 days one year in ten and falls short of 139 one year in ten. On average 132 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 15 days longer, to about May 17, and return around September 30. Severe cold of 16°F or below comes every winter, usually between November 22 and March 1.

July is the warmest month at Pocatello City, ID, averaging 91°F by day and 59°F at night; December is the coldest at 36°F and 21°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 55% of years.

Warmth for growing adds up to 2,830 growing degree days a year (base 50°F), more than at 79% of the 67 Idaho stations. 29% of them (816) have built up by the end of June, and July adds the most, 770. Precipitation totals 13.2 inches a year, most in May (1.5") and least in July (0.6"); May to September bring 39% of it.

The nearest other station, Fort Hall 1 NNE, ID, 14 miles north of Pocatello, has a last frost 18 days later (May 20), a first frost 21 days earlier (September 20), a season 42 days shorter.

The first measurable snow (0.1 inch or more) in Pocatello usually arrives around November 1, and the last of the season around April 12. Those are the middle dates across the winters of 1991–2020 at Pocatello City, ID, 3.4 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 20 days after the last snow.

ZIP 83204 is 3 miles from Pocatello City, ID, which stands at 4,460 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 83201 (Pocatello). The 2023 USDA Plant Hardiness Zone Map lists ZIP 83204 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.