Frost Dates for 81328 — Mancos, Colorado

Half of springs at Mancos 1SW, CO see their last 32°F night by June 4; only one in ten is past it by May 20, and one in ten still has one after June 19. Planting tender crops after June 11 leaves a 30% risk of a frost on them, after June 14 20%, and after June 19 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 56% of the 110 Colorado 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 9 one year in ten, and holds off past October 4 one year in ten. A hard freeze of 28°F follows 8 days later, around October 2; in spring the one-in-ten date for 28°F is June 9, 10 days before the 32°F one. The freeze-free season lasts 111 days in a typical year, shorter than at 76% of the 110 Colorado stations; it reaches 128 days one year in ten and falls short of 90 one year in ten. On average 194 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 11 days longer, to about June 15, and return around September 15. Severe cold of 16°F or below comes every winter, usually between November 1 and April 7.

July is the warmest month at Mancos 1SW, CO, averaging 85°F by day and 51°F at night; January is the coldest at 40°F and 12°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 63% of years.

Warmth for growing adds up to 1,851 growing degree days a year (base 50°F), fewer than at 67% of the 110 Colorado stations. 27% of them (503) have built up by the end of June, and July adds the most, 550. Precipitation totals 15.6 inches a year, most in September (1.9") and least in June (0.6"); May to September bring 44% of it.

The nearest other station, Fort Lewis, CO, 16 miles southeast of Mancos and 717 feet higher, has a last frost 3 days earlier (June 1), a first frost 3 days later (September 27), a season 5 days longer.

The first measurable snow (0.1 inch or more) in Mancos usually arrives around November 16, and the last of the season around April 18. Those are the middle dates across the winters of 1991–2020 at Mancos 1SW, CO, 2.2 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 81328 is 2 miles from Mancos 1SW, CO, which stands at 6,897 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 81328 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.