Frost Dates for 84098 — Park City, Utah

Half of springs at Park City, UT see their last 32°F night by May 29; only one in ten is past it by May 12, 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 16 days between the even-odds date and the one-in-ten date is narrower than at 83% of the 66 Utah stations behind this site's ZIP pages.

In fall the first 32°F night comes by September 25 in half of years, as early as September 12 one year in ten, and holds off past October 9 one year in ten. A hard freeze of 28°F follows 11 days later, around October 6; in spring the one-in-ten date for 28°F is June 1, 13 days before the 32°F one. The freeze-free season lasts 117 days in a typical year, shorter than at 82% of the 66 Utah stations; it reaches 140 days one year in ten and falls short of 97 one year in ten. On average 202 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 12 days longer, to about June 10, and return around September 15. Severe cold of 16°F or below comes every winter, usually between November 9 and March 22.

July is the warmest month at Park City, UT, averaging 80°F by day and 53°F at night; January is the coldest at 33°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 43% of years.

Warmth for growing adds up to 1,616 growing degree days a year (base 50°F), fewer than at 91% of the 66 Utah stations. 24% of them (389) have built up by the end of June, and July adds the most, 516.

The nearest other station, Snake Creek Powerhouse, UT, 13 miles south of Park City and 890 feet lower, has a last frost 2 days later (May 31), a first frost 14 days earlier (September 11), a season 16 days shorter.

The first measurable snow (0.1 inch or more) in Park City usually arrives around October 8, and the last of the season around May 17. Those are the middle dates across the winters of 1991–2020 at Snyderville, UT, 1.6 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 12 days after the last snow.

ZIP 84098 is 5 miles from Park City, UT, which stands at 6,900 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 84098 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.