Rock Springs weather in December: Rock Springs, Wyoming: normal highs, lows, rain and records for December
Rock Springs in December has a normal high of 30°F and a normal low of 13°F, a daily mean of 21°F, falling from 33°F on the 1st to 29°F by the 31st. Measurable precipitation falls on 5 days in a normal December, 0.31 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of −1°C and low of −10°C, 8 mm of precipitation and 15 cm of snow in December.
- NOAA stationRock Springs Airport
- Station IDUSW00024027
- Location41.59°N 109.05°W
- Elevation6,741 ft (2,055 m)
- Population22,967
- Jan 30° 14°
- Feb 33° 16°
- Mar 44° 24°
- Apr 53° 30°
- May 63° 38°
- Jun 75° 47°
- Jul 84° 55°
- Aug 82° 53°
- Sep 71° 44°
- Oct 56° 33°
- Nov 41° 22°
- Dec 30° 13°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Rock Springs in December?
The normal high is 30°F and the normal low 13°F, for a daily mean of 21.4°F. December is 9.8°F cooler than November and 0.1°F cooler than January. December is the 12th warmest month of the year in Rock Springs and the 12th wettest. Across the month the normal high falls 4°F, from 33°F on December 1 to 29°F on December 31. From one year to the next December's mean temperature typically moves about 3.4°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 18°F and 25°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 16%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 33°F | 16°F | 16% | 3% |
| December 8 | 30°F | 14°F | 16% | 3% |
| December 15 | 29°F | 13°F | 16% | 3% |
| December 22 | 28°F | 13°F | 16% | 3% |
| December 31 | 29°F | 13°F | 16% | 3% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 19)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 33°F | 16°F | 16% | 3% | 9 h 20 min |
| December 2 | 33°F | 16°F | 16% | 3% | 9 h 20 min |
| December 3 | 32°F | 15°F | 16% | 3% | 9 h 20 min |
| December 4 | 32°F | 15°F | 16% | 3% | 9 h 20 min |
| December 5 | 31°F | 15°F | 16% | 3% | 9 h 20 min |
| December 6 | 31°F | 14°F | 16% | 3% | 9 h 20 min |
| December 7 | 31°F | 14°F | 16% | 3% | 9 h 20 min |
| December 8 | 30°F | 14°F | 16% | 3% | 9 h 20 min |
| December 9 | 30°F | 14°F | 16% | 3% | 9 h 20 min |
| December 10 | 30°F | 14°F | 16% | 3% | 9 h 10 min |
| December 11 | 30°F | 13°F | 16% | 3% | 9 h 10 min |
| December 12 | 30°F | 13°F | 16% | 3% | 9 h 10 min |
| December 13 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 14 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 15 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 16 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 17 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 18 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 19 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 20 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 21 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 22 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 23 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 24 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 25 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 26 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 27 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 28 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 29 | 28°F | 13°F | 16% | 3% | 9 h 10 min |
| December 30 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
| December 31 | 29°F | 13°F | 16% | 3% | 9 h 10 min |
- Normal high
- 30°FDecember average
- Normal low
- 13°FDecember average
- Precipitation
- 0.31 inmonth total
- Days with precipitation
- 50.01 inch or more
- Snowfall
- 5.8 inmonth total
- Nights at 32°F or colder
- 31
- Daylight
- 9 h 20 min to 9 h 10 minDecember 1 to December 31
- Sunshine
- 68%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024027; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Rock Springs in December?
On a given December day the chance of 0.01 inch or more is 16% on average, highest around December 31 (16%). In all, 0.31 in falls on 5 days of a normal December.
In a normal December in Rock Springs, 31 nights fall to freezing, 18 days stay below freezing all day and snowfall averages 5.8 inches.
Snow falls on 6 days in a normal December, and an inch or more covers the ground on 17 days.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024027.
How humid and windy is Rock Springs in December?
At 3 p.m. the normal temperature is 26°F with 57% relative humidity and a dew point of 13°F; at 6 a.m. it is 16°F with 72% humidity. The wind averages 11.9 mph, most often from the west-southwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 16°F | 9°F | 72% | 10.9 mph | 63% |
| 9 a.m. | 17°F | 9°F | 72% | 10.1 mph | 61% |
| noon | 24°F | 12°F | 62% | 12.7 mph | 63% |
| 3 p.m. | 26°F | 13°F | 57% | 13.8 mph | 63% |
| 6 p.m. | 22°F | 12°F | 65% | 12.7 mph | 65% |
| 9 p.m. | 20°F | 11°F | 68% | 12.3 mph | 70% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024027. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for December in Rock Springs?
The warmest December temperature on this station's record (since 1948) is 59°F, on December 22, 2025; the coldest is −29°F, on December 31, 1978. The wettest December brought 1.78 in (1975); the snowiest, 19.4 inches (1975).
The December mean against the 1991-2020 normal of 21.4°F: 2021 27.0°F (+5.6), 2023 25.6°F (+4.2), 2024 27.2°F (+5.8), 2025 35.6°F (+14.2). 4 of 4 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 27.0°F | +5.6°F | 0.24 in |
| 2023 | 25.6°F | +4.2°F | 0.02 in |
| 2024 | 27.2°F | +5.8°F | 0.18 in |
| 2025 | 35.6°F | +14.2°F | 0.10 in |
Source: records: ACIS, station USW00024027; recent months: ACIS, station USW00024027. Records and recent months use complete months only.
How does December in Rock Springs compare across Wyoming?
Across the 71 places PlainClimate covers in Wyoming, December normal highs run from 24°F in Bondurant to 43°F in Yoder; Rock Springs's is 30°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Rock Springs in November41°F by day, 22°F at night
- Rock Springs in January30°F by day, 14°F at night
- Rock Springs through the yearEvery month, frost dates, records and recent years
- Wyoming in DecemberThe statewide normal and the warmest and coolest places
- Yoder: Wyoming's warmest Decembernormal high 43°F