Frost Dates for 80734 — Holyoke, Colorado

Half of springs at Holyoke, CO see their last 32°F night by May 11; only one in ten is past it by April 30, and one in ten still has one after May 23. Planting tender crops after May 15 leaves a 30% risk of a frost on them, after May 18 20%, and after May 23 10%. The 12 days between the even-odds date and the one-in-ten date is narrower than at 81% 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 13 one year in ten. A hard freeze of 28°F follows 9 days later, around October 12; in spring the one-in-ten date for 28°F is May 14, 9 days before the 32°F one. The freeze-free season lasts 144 days in a typical year, longer than at 53% of the 110 Colorado stations; it reaches 160 days one year in ten and falls short of 125 one year in ten. On average 170 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 9 days longer, to about May 20, and return around September 25. Severe cold of 16°F or below comes every winter, usually between November 5 and March 30.

July is the warmest month at Holyoke, CO, averaging 88°F by day and 59°F at night; January is the coldest at 42°F and 13°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 89% of years.

Warmth for growing adds up to 2,755 growing degree days a year (base 50°F), more than at 65% of the 110 Colorado stations. 32% of them (871) have built up by the end of June, and July adds the most, 722. Precipitation totals 17.9 inches a year, most in May (2.8") and least in January (0.3"); May to September bring 68% of it.

The nearest other station, Imperial, NE, 35 miles east of Holyoke and 486 feet lower, has a last frost 4 days earlier (May 7), a first frost 2 days later (October 5), a season 6 days longer.

The first measurable snow (0.1 inch or more) in Holyoke usually arrives around October 28, and the last of the season around April 12. Those are the middle dates across the winters of 1991–2020 at Holyoke, CO, 3.2 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 29 days after the last snow.

ZIP 80734 is 3 miles from Holyoke, CO, which stands at 3,780 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 80734 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°C) over 1991–2020; a zone describes winter lows, not frost dates.