Frost Dates for 81623 — Carbondale, Colorado

Half of springs at Glenwood Spgs #2, CO see their last 32°F night by May 13; only one in ten is past it by April 30, and one in ten still has one after May 30. Planting tender crops after May 20 leaves a 30% risk of a frost on them, after May 24 20%, and after May 30 10%. The 17 days between the even-odds date and the one-in-ten date is wider than at 85% of the 110 Colorado stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 3 in half of years, as early as September 20 one year in ten, and holds off past October 15 one year in ten. A hard freeze of 28°F follows 11 days later, around October 14; in spring the one-in-ten date for 28°F is May 11, 19 days before the 32°F one. The freeze-free season lasts 142 days in a typical year, shorter than at 50% of the 110 Colorado stations; it reaches 159 days one year in ten and falls short of 120 one year in ten. On average 174 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 17 days longer, to about May 30, and return around September 23. Severe cold of 16°F or below comes every winter, usually between November 13 and March 10.

July is the warmest month at Glenwood Spgs #2, CO, averaging 89°F by day and 53°F at night; January is the coldest at 36°F and 12°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 87% of years.

Warmth for growing adds up to 2,323 growing degree days a year (base 50°F), fewer than at 54% of the 110 Colorado stations. 29% of them (665) have built up by the end of June, and July adds the most, 651. Precipitation totals 15.7 inches a year, most in May (1.7") and least in June (1.0"); May to September bring 43% of it.

The nearest other station, Shoshone, CO, 16 miles north of Carbondale, has a last frost 12 days earlier (May 1), a first frost 11 days later (October 14), a season 22 days longer.

The first measurable snow (0.1 inch or more) in Carbondale usually arrives around November 13, and the last of the season around March 12. Those are the middle dates across the winters of 1991–2020 at Glenwood Spgs #2, CO, 14.4 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 62 days after the last snow.

ZIP 81623 is 14 miles from Glenwood Spgs #2, CO, which stands at 5,895 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 81623 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.