St. George, Utah climate: Normal weather by month, frost dates and records
St. George's normal year runs from 28°F December nights to 102°F July afternoons, with 9.3 inches of precipitation and 1 inch of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 17.1°C, December lows of −2°C, July highs of 39°C, 236 mm of precipitation a year.
- NOAA stationSt George
- Station IDUSC00427516
- Location37.12°N 113.61°W
- Elevation2,857 ft (871 m)
- Population106,288
On October 23, the normal high in St. George is 75°F and the normal low 44°F, and the chance of measurable rain or snow is 10%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for St. George.
- Jan 54° 28°
- Feb 59° 32°
- Mar 68° 39°
- Apr 75° 46°
- May 85° 56°
- Jun 96° 65°
- Jul 102° 72°
- Aug 100° 70°
- Sep 92° 61°
- Oct 79° 47°
- Nov 64° 35°
- Dec 53° 28°
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 St. George each month?
July is the warmest month, with normal highs of 102°F; December the coldest, with normal lows of 28°F. The most precipitation falls in February (1.38 in), the least in June (0.16 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 54°F | 28°F | 41.2°F | 1.22 | 0.5 | 5 | <1 | 20 | 9 h 50 min |
| February | 59°F | 32°F | 45.8°F | 1.38 | 0.5 | 6 | <1 | 10 | 10 h 50 min |
| March | 68°F | 39°F | 53.4°F | 1.02 | 0.2 | 5 | <1 | 2 | 11 h 50 min |
| April | 75°F | 46°F | 60.4°F | 0.66 | 0.0 | 3 | 2 | <1 | 13 h 10 min |
| May | 85°F | 56°F | 70.5°F | 0.33 | 0.0 | 3 | 13 | <1 | 14 h 10 min |
| June | 96°F | 65°F | 80.4°F | 0.16 | 0.0 | 1 | 26 | <1 | 14 h 40 min |
| July | 102°F | 72°F | 86.8°F | 0.50 | 0.0 | 3 | 31 | <1 | 14 h 30 min |
| August | 100°F | 70°F | 85.1°F | 1.07 | 0.0 | 3 | 30 | <1 | 13 h 40 min |
| September | 92°F | 61°F | 76.5°F | 0.67 | 0.0 | 2 | 23 | <1 | 12 h 30 min |
| October | 79°F | 47°F | 63.0°F | 0.77 | 0.0 | 3 | 4 | <1 | 11 h 20 min |
| November | 64°F | 35°F | 49.2°F | 0.67 | 0.0 | 3 | <1 | 8 | 10 h 10 min |
| December | 53°F | 28°F | 40.4°F | 0.86 | 0.0 | 5 | <1 | 22 | 9 h 40 min |
| Year (annual) | 77°F | 48°F | 62.7°F | 9.31 | 1.2 | 42 | 128 | 63 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 12°C | −2°C | 5.1°C | 31 mm | 1 cm |
| February | 15°C | 0°C | 7.7°C | 35 mm | 1 cm |
| March | 20°C | 4°C | 11.9°C | 26 mm | 1 cm |
| April | 24°C | 8°C | 15.8°C | 17 mm | 0 cm |
| May | 30°C | 13°C | 21.4°C | 8 mm | 0 cm |
| June | 36°C | 18°C | 26.9°C | 4 mm | 0 cm |
| July | 39°C | 22°C | 30.4°C | 13 mm | 0 cm |
| August | 38°C | 21°C | 29.5°C | 27 mm | 0 cm |
| September | 34°C | 16°C | 24.7°C | 17 mm | 0 cm |
| October | 26°C | 8°C | 17.2°C | 20 mm | 0 cm |
| November | 18°C | 2°C | 9.6°C | 17 mm | 0 cm |
| December | 12°C | −2°C | 4.7°C | 22 mm | 0 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00427516; 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 St. George?
Normal highs sit between 65°F and 85°F in March, April and October. Of those, April has the fewest days with rain (3).
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 USC00427516.
When is the last frost in St. George?
In St. George, the last spring frost (32°F) comes after March 14 in half of years and after April 6 in one year in ten; the first autumn frost comes before November 10 in half of years and before October 27 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
- March 141 year in 10 after April 6; 9 in 10 after February 27
- First autumn frost, half of years before
- November 101 year in 10 before October 27; 9 in 10 before November 22
NOAA puts the median frost-free season at 239 days, and the season without a hard freeze (28°F) at 266 days.
A hard freeze (28°F) comes after February 27 in half of springs and before November 20 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts St. George in zone 8b across its 2 ZIP code areas (8b in 84790, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, St. George's NOAA station is in zone 8b: the coldest night of a typical year reaches 19°F (20 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 USC00427516; 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.
What hardiness zone is each St. George ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. St. George's 2 ZIP code areas are all in zone 8b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in St. George?
In a normal year in St. George, 128 days a year reach 90°F (63 of them 100°F or more), 63 nights fall to 32°F or colder and 42 days bring measurable precipitation.
- Days at 90°F or more
- 128a normal year
- Days at 100°F or more
- 63a normal year
- Nights at 32°F or colder
- 63a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 42a normal year
- Days with 1 inch of snow or more
- fewer than 1a normal year
The highest temperature in this station's record (since 1893) is 117°F, on July 5, 1985; the lowest is −11°F, on January 26, 1937.
The wettest calendar year on that record is 2019, with 16.17 in; the snowiest season is 1948–49, with 16.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00427516; records: ACIS (NOAA Regional Climate Centers), station USC00427516. Records use complete months only; a month missing more than three days is left out.
How sunny is St. George?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around St. George, 5.4 kWh per square metre a day. June is the sunniest month (93%) and December the cloudiest (76%). Among the 459 U.S. places of 50,000 or more, that ranks tied 58th (with 22 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 79% | 2.8 |
| February | 78% | 3.7 |
| March | 82% | 5.2 |
| April | 85% | 6.5 |
| May | 88% | 7.6 |
| June | 93% | 8.4 |
| July | 88% | 7.5 |
| August | 90% | 7.0 |
| September | 91% | 6.0 |
| October | 88% | 4.5 |
| November | 84% | 3.2 |
| December | 76% | 2.4 |
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 St. George need?
A normal year in St. George brings 3,205 heating degree days, 40% fewer than the median U.S. place (5,373), and 2,416 cooling degree days, 2.7 times the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 5,546 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 738 | 0 |
| February | 536 | 0 |
| March | 362 | 2 |
| April | 170 | 31 |
| May | 38 | 207 |
| June | 2 | 466 |
| July | 0 | 676 |
| August | 0 | 623 |
| September | 5 | 351 |
| October | 121 | 61 |
| November | 473 | 0 |
| December | 761 | 0 |
| Year (annual) | 3,205 | 2,416 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00427516. 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 St. George been warmer than normal lately?
2025 averaged 65.0°F, 2.3°F above the 1991-2020 normal of 62.7°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 65.0°F | +2.3°F | 8.84 | 2.7 |
| 2022 | 64.2°F | +1.5°F | 5.88 | 0.0 |
| 2023 | 62.3°F | −0.4°F | 14.53 | 0.0 |
| 2024 | 65.2°F | +2.5°F | 7.18 | 0.0 |
| 2025 | 65.0°F | +2.3°F | 6.51 | 0.0 |
Over 78 complete years from 1890 to 2025, the station's annual mean temperature rose at a fitted 0.2°F per century (+0.01°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00427516; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does St. George's climate compare?
St. George is warmer than 96 of the other 96 places with their own NOAA record in Utah, and wetter than 25. Across the 7,247 U.S. stations with normals, its annual mean of 62.7°F is warmer than 82%.
In the Köppen classification computed from these normals, St. George is BWk: cold desert. 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 St. George share this climate record?
3 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.
- Washington, UT35,501 people · 7 mi E
- Ivins, UT11,108 people · 6 mi NW
- Santa Clara, UT8,631 people · 3 mi W
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 St. George's climate
What is the coldest month in St. George?
December, with a normal high of 53°F and a normal low of 28°F. The warmest is July (102°F by day, 72°F at night).
Does it snow in St. George?
Yes: 1 inch in a normal year, falling on 1 days with 0.1 inch or more, the most in January (0.5 inches).
What is the rainiest month in St. George?
February, with 1.38 in of precipitation in a normal year; the driest is June with 0.16 in.
What plant hardiness zone is St. George in?
The USDA's 2023 map puts St. George in zone 8b across its 2 ZIP code areas (8b in 84790, the largest). By the same method at St. George's NOAA station, the coldest night of a typical year reaches 19°F (20 years, 1991-2020): zone 8b.
How late can frost come in St. George?
In half of years the last 32°F night comes after March 14; in one year in ten it comes after April 6. Waiting until April 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- St. George in OctoberThis month day by day, its records and recent years
- Utah climateThe statewide normals and every place in the state
- Veyo, UT16 miles from this station, 56.6°F a year
- La Verkin, UT19 miles from this station, 60.8°F a year
- Lytle Ranch, UT23 miles from this station, 62.8°F a year
- Beaver Dam, AZ24 miles from this station, 68.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made