USDA Hardiness Zone 6a
Frost Dates for 84060 — Park City, Utah
NOAA 1991–2020 normals from Park City, UT (6,900 ft), under a mile northwest.
Updated
In Park City, the last spring frost (32°F) is around May 29 in half of years and has passed by June 14 in nine years out of ten. The first fall frost comes around September 25, as early as September 12 one year in ten, leaving a typical freeze-free season of 117 days (NOAA, Park City, UT).
- Last spring frost
- May 29
- First fall frost
- September 25
- Growing season
- 117 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- October 13
- Last snow
- May 7
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
18 of 18 observed
NOAA normal
Frost risk by date in Park City
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.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 26 | May 31 | Jun 4 | Jun 7 | Jun 10 | Jun 14 | Jun 18 | Jun 22 | Jun 27 |
| 32°F | May 12 | May 17 | May 22 | May 26 | May 29 | Jun 1 | Jun 4 | Jun 8 | Jun 14 |
| 28°F | Apr 25 | Apr 30 | May 4 | May 9 | May 12 | May 16 | May 20 | May 25 | Jun 1 |
| 24°F | Apr 8 | Apr 14 | Apr 18 | Apr 22 | Apr 27 | Apr 30 | May 3 | May 7 | May 14 |
| 20°F | Mar 19 | Mar 27 | Apr 1 | Apr 5 | Apr 7 | Apr 11 | Apr 15 | Apr 20 | Apr 29 |
| 16°F | Mar 3 | Mar 8 | Mar 13 | Mar 17 | Mar 22 | Mar 27 | Apr 1 | Apr 5 | Apr 11 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 3 | Sep 7 | Sep 10 | Sep 13 | Sep 15 | Sep 18 | Sep 21 | Sep 23 | Sep 27 |
| 32°F | Sep 12 | Sep 17 | Sep 20 | Sep 23 | Sep 25 | Sep 28 | Sep 30 | Oct 3 | Oct 9 |
| 28°F | Sep 23 | Sep 29 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 13 | Oct 17 | Oct 21 |
| 24°F | Oct 4 | Oct 10 | Oct 14 | Oct 17 | Oct 20 | Oct 24 | Oct 26 | Oct 30 | Nov 3 |
| 20°F | Oct 17 | Oct 21 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 14 |
| 16°F | Oct 25 | Oct 29 | Nov 2 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 23 |
Freeze probabilities 1991–2020 at Park City, UT, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 84060 →Compare Park City with another place →
Weather by month in Park City
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.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 33 | 16 | 100% | 31 | 0 |
| Feb | 35 | 17 | 100% | 28 | 0 |
| Mar | 43 | 25 | 100% | 28 | 1 |
| Apr | 51 | 31 | 100% | 22 | 11 |
| May | 61 | 38 | 99% | 10 | 92 |
| Jun | 72 | 46 | 43% | 3 | 285 |
| Jul | 80 | 53 | 0% | 0 | 516 |
| Aug | 79 | 52 | 0% | <1 | 470 |
| Sep | 69 | 43 | 71% | 6 | 205 |
| Oct | 56 | 33 | 100% | 19 | 34 |
| Nov | 42 | 23 | 100% | 26 | 2 |
| Dec | 33 | 16 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Park City, UT (6,900 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Snake Creek Powerhouse, UT, 7 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.
When it snows in Park City, Utah
The first measurable snow (0.1 inch or more) in Park City usually arrives around October 13, and the last of the season around May 7. Those are the middle dates across the winters of 1991–2020 at Park City, UT, 0.8 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 22 days after the last snow.
Planting calendar for 84060
| When | What to do |
|---|---|
| March 20 – April 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| April 3 – April 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| May 1 – May 15 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 29 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 3 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 11 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 25 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 84060 is under a mile 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; its figures are presented in full for 84098 (Park City). The 2023 USDA Plant Hardiness Zone Map lists ZIP 84060 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.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.