Helena weather in December: Helena, Montana: normal highs, lows, rain and records for December
Helena in December has a normal high of 33°F and a normal low of 14°F, a daily mean of 23°F, falling from 36°F on the 1st to 31°F by the 31st. Measurable precipitation falls on 7 days in a normal December, 0.46 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 0°C and low of −10°C, 12 mm of precipitation and 20 cm of snow in December.
- NOAA stationHelena Regional Airport
- Station IDUSW00024144
- Location46.61°N 111.96°W
- Elevation3,828 ft (1,167 m)
- From the center3 miles
- Population34,729
- Jan 32° 14°
- Feb 37° 17°
- Mar 48° 25°
- Apr 57° 32°
- May 66° 42°
- Jun 75° 49°
- Jul 86° 55°
- Aug 85° 53°
- Sep 73° 45°
- Oct 58° 34°
- Nov 43° 23°
- Dec 33° 14°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Helena in December?
The normal high is 33°F and the normal low 14°F, for a daily mean of 23.4°F. December is 9.4°F cooler than November and 0.4°F warmer than January. December is the 11th warmest month of the year in Helena and the 10th wettest, and the snowiest. Across the month the normal high falls 5°F, from 36°F on December 1 to 31°F on December 31. From one year to the next December's mean temperature typically moves about 5.1°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 18°F and 29°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 22%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 36°F | 18°F | 21% | 6% |
| December 8 | 34°F | 16°F | 21% | 5% |
| December 15 | 32°F | 14°F | 21% | 5% |
| December 22 | 31°F | 13°F | 21% | 5% |
| December 31 | 31°F | 12°F | 22% | 5% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 28)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 36°F | 18°F | 21% | 6% | 8 h 50 min |
| December 2 | 36°F | 18°F | 21% | 6% | 8 h 50 min |
| December 3 | 36°F | 17°F | 21% | 6% | 8 h 50 min |
| December 4 | 35°F | 17°F | 21% | 6% | 8 h 50 min |
| December 5 | 35°F | 17°F | 21% | 5% | 8 h 50 min |
| December 6 | 35°F | 16°F | 21% | 5% | 8 h 40 min |
| December 7 | 34°F | 16°F | 21% | 5% | 8 h 40 min |
| December 8 | 34°F | 16°F | 21% | 5% | 8 h 40 min |
| December 9 | 34°F | 16°F | 21% | 5% | 8 h 40 min |
| December 10 | 33°F | 15°F | 21% | 5% | 8 h 40 min |
| December 11 | 33°F | 15°F | 21% | 5% | 8 h 40 min |
| December 12 | 33°F | 15°F | 21% | 5% | 8 h 40 min |
| December 13 | 33°F | 14°F | 21% | 5% | 8 h 40 min |
| December 14 | 32°F | 14°F | 21% | 5% | 8 h 40 min |
| December 15 | 32°F | 14°F | 21% | 5% | 8 h 40 min |
| December 16 | 32°F | 14°F | 21% | 5% | 8 h 40 min |
| December 17 | 32°F | 14°F | 21% | 5% | 8 h 30 min |
| December 18 | 32°F | 13°F | 21% | 5% | 8 h 30 min |
| December 19 | 32°F | 13°F | 21% | 5% | 8 h 30 min |
| December 20 | 31°F | 13°F | 21% | 5% | 8 h 30 min |
| December 21 | 31°F | 13°F | 21% | 5% | 8 h 30 min |
| December 22 | 31°F | 13°F | 21% | 5% | 8 h 30 min |
| December 23 | 31°F | 13°F | 21% | 5% | 8 h 30 min |
| December 24 | 31°F | 13°F | 22% | 5% | 8 h 30 min |
| December 25 | 31°F | 12°F | 22% | 5% | 8 h 30 min |
| December 26 | 31°F | 12°F | 22% | 5% | 8 h 30 min |
| December 27 | 31°F | 12°F | 22% | 5% | 8 h 30 min |
| December 28 | 31°F | 12°F | 22% | 5% | 8 h 40 min |
| December 29 | 31°F | 12°F | 22% | 5% | 8 h 40 min |
| December 30 | 31°F | 12°F | 22% | 5% | 8 h 40 min |
| December 31 | 31°F | 12°F | 22% | 5% | 8 h 40 min |
- Normal high
- 33°FDecember average
- Normal low
- 14°FDecember average
- Precipitation
- 0.46 inmonth total
- Days with precipitation
- 70.01 inch or more
- Snowfall
- 7.7 inmonth total
- Nights at 32°F or colder
- 30
- Daylight
- 8 h 50 min to 8 h 40 minDecember 1 to December 31
- Sunshine
- 64%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00024144; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Helena in December?
On a given December day the chance of 0.01 inch or more is 21% on average, highest around December 29 (22%). In all, 0.46 in falls on 7 days of a normal December.
In a normal December in Helena, 30 nights fall to freezing, 13 days stay below freezing all day and snowfall averages 7.7 inches.
Snow falls on 5 days in a normal December, and an inch or more covers the ground on 14 days.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00024144.
How humid and windy is Helena in December?
At 3 p.m. the normal temperature is 26°F with 59% relative humidity and a dew point of 14°F; at 6 a.m. it is 17°F with 74% humidity. The wind averages 5.1 mph, most often from the west in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 17°F | 10°F | 74% | 4.8 mph | – |
| 9 a.m. | 17°F | 10°F | 74% | 4.5 mph | – |
| noon | 23°F | 13°F | 65% | 5.4 mph | – |
| 3 p.m. | 26°F | 14°F | 59% | 6.2 mph | 52% |
| 6 p.m. | 23°F | 13°F | 67% | 5.5 mph | 54% |
| 9 p.m. | 20°F | 13°F | 71% | 5.0 mph | 52% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024144. 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 Helena?
The warmest December temperature on Helena's official record (since 1880) is 70°F, on December 1, 2021; the coldest is −40°F, on December 30, 1880. The wettest December brought 4.64 in (1880); the snowiest, 46.4 inches (1880).
The December mean against the 1991-2020 normal of 23.4°F: 2021 25.3°F (+1.9), 2022 18.2°F (−5.2), 2023 32.0°F (+8.6), 2024 35.2°F (+11.8), 2025 34.0°F (+10.6). 4 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 25.3°F | +1.9°F | 0.98 in |
| 2022 | 18.2°F | −5.2°F | 0.69 in |
| 2023 | 32.0°F | +8.6°F | 0.03 in |
| 2024 | 35.2°F | +11.8°F | 0.30 in |
| 2025 | 34.0°F | +10.6°F | 0.86 in |
Source: records: ACIS, NWS threaded record HLNthr; recent months: ACIS, station USW00024144. Records and recent months use complete months only.
How does December in Helena compare across Montana?
Across the 141 places PlainClimate covers in Montana, December normal highs run from 22°F in Cooke City to 39°F in Geraldine; Helena's is 33°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.