Frost Dates for 80701 — Fort Morgan, Colorado

Half of springs at Fort Morgan, CO see their last 32°F night by May 6; only one in ten is past it by April 23, and one in ten still has one after May 19. Planting tender crops after May 10 leaves a 30% risk of a frost on them, after May 13 20%, and after May 19 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 67% of the 110 Colorado stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 6 in half of years, as early as September 24 one year in ten, and holds off past October 18 one year in ten. A hard freeze of 28°F follows 9 days later, around October 15; in spring the one-in-ten date for 28°F is May 9, 10 days before the 32°F one. The freeze-free season lasts 153 days in a typical year, longer than at 66% of the 110 Colorado stations; it reaches 168 days one year in ten and falls short of 135 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 15, and return around September 28. Severe cold of 16°F or below comes every winter, usually between November 7 and March 19.

July is the warmest month at Fort Morgan, CO, averaging 90°F by day and 60°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 73% of years.

Warmth for growing adds up to 2,972 growing degree days a year (base 50°F), more than at 76% of the 110 Colorado stations. 32% of them (950) have built up by the end of June, and July adds the most, 773. Precipitation totals 14.3 inches a year, most in July (2.4") and least in January (0.3"); May to September bring 67% of it.

The nearest other station, Woodrow 6NNE, CO, 16 miles southeast of Fort Morgan, has a last frost 9 days later (May 15), a first frost 5 days earlier (October 1), a season 13 days shorter.

The first measurable snow (0.1 inch or more) in Fort Morgan usually arrives around November 16, and the last of the season around April 7. Those are the middle dates across the winters of 1991–2020 at Fort Morgan, CO, 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 29 days after the last snow.

ZIP 80701 is 4 miles from Fort Morgan, CO, which stands at 4,376 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 80701 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.