Mountain Dell Dam, Utah climate: Climate normals at a NOAA weather station
Mountain Dell Dam's normal year runs from 20°F January nights to 89°F July afternoons, with 25.0 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.2°C, January lows of −7°C, July highs of 32°C, 636 mm of precipitation a year.
- NOAA stationMountain Dell Dam
- Station IDUSC00425892
- Location40.75°N 111.72°W
- Elevation5,420 ft (1,652 m)
On October 23, the normal high in Mountain Dell Dam is 61°F and the normal low 36°F, and the chance of measurable rain or snow is 31%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mountain Dell Dam.
- Jan 40° 20°
- Feb 44° 24°
- Mar 54° 30°
- Apr 60° 36°
- May 70° 43°
- Jun 81° 49°
- Jul 89° 57°
- Aug 88° 56°
- Sep 79° 48°
- Oct 65° 38°
- Nov 50° 30°
- Dec 40° 22°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Mountain Dell Dam each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 20°F. The most precipitation falls in April (3.28 in), the least in July (0.80 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 40°F | 20°F | 30.1°F | 2.48 | 12 | <1 | 29 | 9 h 30 min |
| February | 44°F | 24°F | 33.9°F | 2.05 | 11 | <1 | 25 | 10 h 40 min |
| March | 54°F | 30°F | 41.9°F | 2.59 | 11 | <1 | 24 | 11 h 50 min |
| April | 60°F | 36°F | 47.9°F | 3.28 | 12 | <1 | 14 | 13 h 20 min |
| May | 70°F | 43°F | 56.6°F | 3.11 | 11 | <1 | 4 | 14 h 30 min |
| June | 81°F | 49°F | 65.0°F | 1.56 | 6 | 4 | <1 | 15 h |
| July | 89°F | 57°F | 72.9°F | 0.80 | 4 | 16 | <1 | 14 h 50 min |
| August | 88°F | 56°F | 71.8°F | 0.80 | 7 | 9 | <1 | 13 h 50 min |
| September | 79°F | 48°F | 63.2°F | 1.79 | 8 | 1 | 1 | 12 h 30 min |
| October | 65°F | 38°F | 51.4°F | 2.28 | 10 | <1 | 10 | 11 h 10 min |
| November | 50°F | 30°F | 39.8°F | 2.12 | 9 | <1 | 22 | 10 h |
| December | 40°F | 22°F | 30.6°F | 2.17 | 13 | <1 | 29 | 9 h 20 min |
| Year (annual) | 63°F | 38°F | 50.4°F | 25.03 | 114 | 29 | 158 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −7°C | −1.1°C | 63 mm |
| February | 7°C | −5°C | 1.1°C | 52 mm |
| March | 12°C | −1°C | 5.5°C | 66 mm |
| April | 16°C | 2°C | 8.8°C | 83 mm |
| May | 21°C | 6°C | 13.7°C | 79 mm |
| June | 27°C | 10°C | 18.3°C | 40 mm |
| July | 32°C | 14°C | 22.7°C | 20 mm |
| August | 31°C | 13°C | 22.1°C | 20 mm |
| September | 26°C | 9°C | 17.3°C | 45 mm |
| October | 18°C | 3°C | 10.8°C | 58 mm |
| November | 10°C | −1°C | 4.3°C | 54 mm |
| December | 4°C | −6°C | −0.8°C | 55 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, City Creek Water Treatment Plant (7 miles away), gets 114 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00425892; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Mountain Dell Dam?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, June has the fewest days with rain (6).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00425892.
When is the last frost at Mountain Dell Dam?
In Mountain Dell Dam, the last spring frost (32°F) comes after May 7 in half of years and after May 27 in one year in ten; the first autumn frost comes before October 14 in half of years and before September 29 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 71 year in 10 after May 27; 9 in 10 after April 21
- First autumn frost, half of years before
- October 141 year in 10 before September 29; 9 in 10 before October 27
NOAA puts the median frost-free season at 158 days, and the season without a hard freeze (28°F) at 188 days.
A hard freeze (28°F) comes after April 21 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mountain Dell Dam in zone 6b in ZIP code 84109, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6b: the coldest night of a typical year reaches −4°F (18 complete years).
Frost dates for every NOAA station in Utah · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00425892; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Mountain Dell Dam?
In a normal year in Mountain Dell Dam, 29 days a year reach 90°F, 158 nights fall to 32°F or colder and 114 days bring measurable precipitation.
- Days at 90°F or more
- 29a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 158a normal year
- Days that stay below freezing
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 114a normal year
The highest temperature in this station's record (since 1927) is 102°F, on July 26, 1960; the lowest is −21°F, on January 18, 1984.
The wettest calendar year on that record is 1983, with 38.80 in; the snowiest season is 1948–49, with 177.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00425892; records: ACIS (NOAA Regional Climate Centers), station USC00425892. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Mountain Dell Dam?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds at Mountain Dell Dam, 4.8 kWh per square metre a day. July is the sunniest month (88%) and December the cloudiest (67%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 71% | 2.3 |
| February | 72% | 3.2 |
| March | 75% | 4.5 |
| April | 74% | 5.6 |
| May | 77% | 6.6 |
| June | 86% | 7.8 |
| July | 88% | 7.5 |
| August | 86% | 6.6 |
| September | 85% | 5.4 |
| October | 80% | 3.8 |
| November | 72% | 2.5 |
| December | 67% | 1.9 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Mountain Dell Dam record?
A normal year at Mountain Dell Dam brings 5,904 heating degree days, 10% more than the median U.S. place (5,373), and 617 cooling degree days, 32% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,678 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,080 | 0 |
| February | 871 | 0 |
| March | 718 | 0 |
| April | 515 | 0 |
| May | 273 | 11 |
| June | 84 | 83 |
| July | 3 | 249 |
| August | 6 | 218 |
| September | 109 | 55 |
| October | 424 | 1 |
| November | 755 | 0 |
| December | 1,066 | 0 |
| Year (annual) | 5,904 | 617 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00425892. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Mountain Dell Dam been warmer than normal?
2025 averaged 49.4°F, 1.0°F below the 1991-2020 normal of 50.4°F. 0 of the 4 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 48.9°F | −1.5°F | 29.75 |
| 2022 | 46.6°F | −3.8°F | 25.45 |
| 2023 | 46.6°F | −3.8°F | 29.53 |
| 2025 | 49.4°F | −1.0°F | 21.94 |
Over 46 complete years from 1949 to 2025, the station's annual mean temperature rose at a fitted 3.3°F per century (+0.18°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00425892; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Mountain Dell Dam's climate compare?
Mountain Dell Dam is warmer than 55 of the 97 places with their own NOAA record in Utah, and wetter than 87. Across the 7,247 U.S. stations with normals, its annual mean of 50.4°F is warmer than 42%.
In the Köppen classification computed from these normals, Mountain Dell Dam is Dsa: continental, dry-summer, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Mountain Dell Dam share this climate record?
2 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Summit Park, UT8,545 people · 7 mi E
- Emigration Canyon metro township, UT1,572 people · 3 mi N
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Mountain Dell Dam's climate
What is the coldest month at Mountain Dell Dam?
January, with a normal high of 40°F and a normal low of 20°F. The warmest is July (89°F by day, 57°F at night).
Does it snow at Mountain Dell Dam?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, City Creek Water Treatment Plant (7 miles away), records 114 inches of snow in a normal year.
What is the rainiest month at Mountain Dell Dam?
April, with 3.28 in of precipitation in a normal year; the driest is July with 0.80 in.
What plant hardiness zone is Mountain Dell Dam in?
The USDA's 2023 map puts Mountain Dell Dam in zone 6b in ZIP code 84109, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −4°F (18 years, 1991-2020): zone 6b.
How late can frost come at Mountain Dell Dam?
In half of years the last 32°F night comes after May 7; in one year in ten it comes after May 27. Waiting until May 27 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Utah climateThe statewide normals and every place in the state
- City Creek Water Treatment Plant, UT7 miles from this station, 49.2°F a year
- Salt Lake Triad Center, UT9 miles from this station, 55.8°F a year
- Cottonwood Heights, UT9 miles from this station, 53.2°F a year
- North Salt Lake, UT11 miles from this station, 51.9°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made