Grantsville, Utah climate: Normal weather by month, frost dates and records
Grantsville's normal year runs from 19°F January nights to 92°F July afternoons, with 11.6 inches of precipitation and 33 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.7°C, January lows of −7°C, July highs of 33°C, 293 mm of precipitation a year.
- NOAA stationGrantsville (2 mi W)
- Station IDUSC00423348
- Location40.60°N 112.51°W
- Elevation4,550 ft (1,387 m)
- Population15,682
On October 23, the normal high in Grantsville is 61°F and the normal low 36°F, and the chance of measurable rain or snow is 19%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Grantsville.
- Jan 37° 19°
- Feb 43° 23°
- Mar 53° 30°
- Apr 61° 36°
- May 71° 45°
- Jun 82° 54°
- Jul 92° 64°
- Aug 90° 62°
- Sep 79° 50°
- Oct 64° 38°
- Nov 49° 28°
- Dec 38° 20°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Grantsville each month?
July is the warmest month, with normal highs of 92°F; January the coldest, with normal lows of 19°F. The most precipitation falls in May (1.53 in), the least in July (0.66 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 37°F | 19°F | 28.1°F | 0.81 | 7.2 | 7 | <1 | 30 | 9 h 30 min |
| February | 43°F | 23°F | 33.0°F | 0.94 | 7.5 | 7 | <1 | 25 | 10 h 40 min |
| March | 53°F | 30°F | 41.7°F | 1.10 | 3.5 | 8 | <1 | 21 | 11 h 50 min |
| April | 61°F | 36°F | 48.0°F | 1.52 | 1.9 | 9 | <1 | 9 | 13 h 10 min |
| May | 71°F | 45°F | 57.8°F | 1.53 | 0.0 | 8 | 1 | 1 | 14 h 20 min |
| June | 82°F | 54°F | 68.3°F | 0.69 | 0.0 | 4 | 9 | <1 | 15 h |
| July | 92°F | 64°F | 77.9°F | 0.66 | 0.0 | 4 | 24 | <1 | 14 h 50 min |
| August | 90°F | 62°F | 76.0°F | 0.73 | 0.0 | 4 | 20 | <1 | 13 h 50 min |
| September | 79°F | 50°F | 64.4°F | 0.90 | 0.0 | 5 | 4 | <1 | 12 h 30 min |
| October | 64°F | 38°F | 51.0°F | 0.91 | 0.1 | 6 | <1 | 6 | 11 h 10 min |
| November | 49°F | 28°F | 38.5°F | 0.93 | 5.0 | 6 | <1 | 21 | 10 h |
| December | 38°F | 20°F | 29.1°F | 0.83 | 7.9 | 8 | <1 | 29 | 9 h 20 min |
| Year (annual) | 63°F | 39°F | 51.2°F | 11.55 | 33.1 | 76 | 58 | 142 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 3°C | −7°C | −2.2°C | 21 mm | 18 cm |
| February | 6°C | −5°C | 0.6°C | 24 mm | 19 cm |
| March | 12°C | −1°C | 5.4°C | 28 mm | 9 cm |
| April | 16°C | 2°C | 8.9°C | 39 mm | 5 cm |
| May | 22°C | 7°C | 14.3°C | 39 mm | 0 cm |
| June | 28°C | 12°C | 20.2°C | 18 mm | 0 cm |
| July | 33°C | 18°C | 25.5°C | 17 mm | 0 cm |
| August | 32°C | 17°C | 24.4°C | 19 mm | 0 cm |
| September | 26°C | 10°C | 18.0°C | 23 mm | 0 cm |
| October | 18°C | 3°C | 10.6°C | 23 mm | 0 cm |
| November | 10°C | −2°C | 3.6°C | 24 mm | 13 cm |
| December | 3°C | −7°C | −1.6°C | 21 mm | 20 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00423348; 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.
When is the best weather to visit Grantsville?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, June has the fewest days with rain (4).
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 USC00423348.
When is the last frost in Grantsville?
In Grantsville, the last spring frost (32°F) comes after May 2 in half of years and after May 19 in one year in ten; the first autumn frost comes before October 14 in half of years and before September 30 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 21 year in 10 after May 19; 9 in 10 after April 17
- First autumn frost, half of years before
- October 141 year in 10 before September 30; 9 in 10 before October 27
NOAA puts the median frost-free season at 164 days, and the season without a hard freeze (28°F) at 189 days.
A hard freeze (28°F) comes after April 17 in half of springs and before October 25 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Grantsville in zone 7a in ZIP code 84074, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Grantsville's NOAA station is in zone 7a: the coldest night of a typical year reaches 1°F (21 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 USC00423348; 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 in Grantsville?
In a normal year in Grantsville, 58 days a year reach 90°F (5 of them 100°F or more), 142 nights fall to 32°F or colder and 76 days bring measurable precipitation.
- Days at 90°F or more
- 58a normal year
- Days at 100°F or more
- 5a normal year
- Nights at 32°F or colder
- 142a normal year
- Days that stay below freezing
- 25high of 32°F or less
- Days with 0.01 inch of precipitation
- 76a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1913) is 106°F, on June 16, 2021; the lowest is −9°F, on January 6, 2017.
The wettest calendar year on that record is 2023, with 14.77 in; the snowiest season is 2010–11, with 64.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00423348; records: ACIS (NOAA Regional Climate Centers), station USC00423348. Records use complete months only; a month missing more than three days is left out.
How sunny is Grantsville?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Grantsville, 4.8 kWh per square metre a day. July is the sunniest month (88%) and December the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 2.1 |
| February | 71% | 3.1 |
| March | 75% | 4.4 |
| April | 77% | 5.8 |
| May | 80% | 6.8 |
| June | 88% | 7.8 |
| July | 88% | 7.4 |
| August | 87% | 6.6 |
| September | 87% | 5.4 |
| October | 82% | 3.9 |
| November | 75% | 2.5 |
| December | 66% | 1.8 |
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 much heating and cooling does Grantsville need?
A normal year in Grantsville brings 6,044 heating degree days, 13% more than the median U.S. place (5,373), and 1,033 cooling degree days, 14% more 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 3,142 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,142 | 0 |
| February | 895 | 0 |
| March | 721 | 0 |
| April | 510 | 1 |
| May | 257 | 33 |
| June | 60 | 158 |
| July | 2 | 403 |
| August | 4 | 345 |
| September | 109 | 89 |
| October | 436 | 4 |
| November | 797 | 0 |
| December | 1,113 | 0 |
| Year (annual) | 6,044 | 1,033 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00423348. 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.
Has Grantsville been warmer than normal lately?
2025 averaged 54.6°F, 3.4°F above the 1991-2020 normal of 51.2°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 53.1°F | +1.9°F | 11.30 | 30.4 |
| 2022 | 51.8°F | +0.6°F | 7.48 | – |
| 2023 | 50.5°F | −0.7°F | 14.77 | 51.6 |
| 2024 | 53.4°F | +2.2°F | 8.92 | 14.2 |
| 2025 | 54.6°F | +3.4°F | 6.99 | 9.2 |
Source: observed years: ACIS, station USC00423348. A year counts only with all twelve months complete.
How does Grantsville's climate compare?
Grantsville is warmer than 65 of the other 96 places with their own NOAA record in Utah, and wetter than 35. Across the 7,247 U.S. stations with normals, its annual mean of 51.2°F is warmer than 46%.
In the Köppen classification computed from these normals, Grantsville is BSk: cold semi-arid steppe. 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.
Questions about Grantsville's climate
What is the coldest month in Grantsville?
January, with a normal high of 37°F and a normal low of 19°F. The warmest is July (92°F by day, 64°F at night).
Does it snow in Grantsville?
Yes: 33 inches in a normal year, falling on 19 days with 0.1 inch or more, the most in December (7.9 inches).
What is the rainiest month in Grantsville?
May, with 1.53 in of precipitation in a normal year; the driest is July with 0.66 in.
What plant hardiness zone is Grantsville in?
The USDA's 2023 map puts Grantsville in zone 7a in ZIP code 84074, the nearest ZIP area. By the same method at Grantsville's NOAA station, the coldest night of a typical year reaches 1°F (21 years, 1991-2020): zone 7a.
How late can frost come in Grantsville?
In half of years the last 32°F night comes after May 2; in one year in ten it comes after May 19. Waiting until May 19 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Utah climateThe statewide normals and every place in the state
- Tooele, UT11 miles from this station, 52.0°F a year
- Garfield, UT18 miles from this station, 54.4°F a year
- Johnson Pass, UT19 miles from this station, 49.8°F a year
- Salt Lake City, UT30 miles from this station, 54.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made