Frost Dates for 80517 — Estes Park, Colorado

Half of springs at Estes Park 3 SSE, CO see their last 32°F night by May 30; only one in ten is past it by May 15, and one in ten still has one after June 14. Planting tender crops after June 4 leaves a 30% risk of a frost on them, after June 8 20%, and after June 14 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 17 in half of years, as early as September 3 one year in ten, and holds off past October 1 one year in ten. A hard freeze of 28°F follows 11 days later, around September 28; in spring the one-in-ten date for 28°F is May 31, 14 days before the 32°F one. The freeze-free season lasts 109 days in a typical year, shorter than at 79% of the 110 Colorado stations; it reaches 130 days one year in ten and falls short of 87 one year in ten. On average 184 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 13 days longer, to about June 12, and return around September 6. Severe cold of 16°F or below comes every winter, usually between October 30 and April 13.

July is the warmest month at Estes Park 3 SSE, CO, averaging 80°F by day and 48°F at night; December is the coldest at 36°F and 16°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 42% of years.

Warmth for growing adds up to 1,377 growing degree days a year (base 50°F), fewer than at 82% of the 110 Colorado stations. 25% of them (351) have built up by the end of June, and July adds the most, 440. Precipitation totals 17.6 inches a year, most in July (2.6") and least in February (0.7"); May to September bring 55% of it.

The nearest other station, Allenspark 3NW, CO, 10 miles south of Estes Park and 688 feet higher, has a last frost 15 days later (June 14), a first frost 5 days earlier (September 12), a season 17 days shorter.

The first measurable snow (0.1 inch or more) in Estes Park usually arrives around October 9, and the last of the season around May 19. Those are the middle dates across the winters of 1991–2020 at Estes Park 3 SSE, CO, 1.5 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 11 days after the last snow.

ZIP 80517 is 2 miles from Estes Park 3 SSE, CO, which stands at 7,812 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 80517 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.