Boise, ID weather in December
Boise is cold in December, with frequent rain and some snow: highs average 39°F and nights drop to about 25°F. There are about 12 days with rain or snow. Snowfall averages about 5.6 in. This is the depth of winter in Boise.
- Normal high
- 39°F
- Normal low
- 25°F
- Wet days
- 12
- 1.5 in total
- Snowfall
- 5.6 in
- snow on the ground 6 days
How December changes from start to finish
| December 1 | December 31 | |
|---|---|---|
| Normal high | 42°F | 37°F |
| Normal low | 28°F | 24°F |
| Chance of a wet day | 37% | 38% |
| Sunrise / sunset | 7:58 am / 5:09 pm | 8:18 am / 5:17 pm |
| Daylight | 9.2 h | 9.0 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Mountain Time).
A typical December day
- 6 am29°Fdew point 23°F
- 9 am29°Fdew point 23°F
- Noon35°Fdew point 25°F
- 3 pm37°Fdew point 26°F
- 6 pm34°Fdew point 26°F
- 9 pm31°Fdew point 25°F
NOAA hourly normals (local standard time) from Boise Air Terminal (4 mi away); average wind 7 mph; clear or few clouds in 49% of daytime hours, mostly cloudy or overcast in 46%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 31
- Hot dayshigh 90°F or more0 of 31
- Muggy daysdaily mean dew point 65°F or more0 of 31
- Wet daysat least 0.01 in of rain or melted snow12 of 31
- Notable rainat least 0.10 in5 of 31
- Freezing nightslow 32°F or below25 of 31
- Snow on the groundsnow depth 1 in or more6 of 31
Average days per December, counted from daily records for each year 1991-2020.
Rain and snow in December
Normal precipitation is 1.5 in; a dry December brings about 0.9 in and a wet one about 1.8 in (25th and 75th percentiles). About 1 day brings half an inch or more. Normal snowfall is 5.6 in, with about 2 days of an inch or more.
How December varies from year to year
- Warmest December, 1991-20202003: average high 44°F
- Coolest December2016: average high 31°F
- Wettest December1996: 3.4 in
- Driest December1991: 0.3 in
- Highest reading63°F (December 11, 2014)
- Lowest reading-7°F (December 9, 2013)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
December compared with November and January
| November | December | January | |
|---|---|---|---|
| Normal high | 49°F | 39°F | 39°F |
| Normal low | 32°F | 25°F | 26°F |
| Wet days | 10 | 12 | 11 |
| Comfortable days | 1 | 0 | 0 |
| Daylight | 9.7 h | 9.0 h | 9.4 h |
Highs change by -10°F from November and 0°F into January.
Nearby alternatives in December
- Cooler: Sun Valley, ID93 mi · high 30°F · 11 wet days
How Boise ranks in December
- Normal high294th warmest of 378 cities; 1st of 2 in Idaho
- Wet days299th driest of 378
- Comfortable days300th most of 340
What to pack for Boise in December
- A warm jacket – lows near 25°F, highs near 39°F
- A rain jacket or umbrella – rain or snow on about 12 days
- Waterproof boots – about 5.6 in of snow in a typical year
- A hat and gloves – about 25 freezing nights
Heating and cooling
December has 1020 heating degree days and 0 cooling degree days (base 65°F), 16% of the year's total heating and cooling demand.
Questions
How cold is Boise in December?
The normal high is 39°F and the normal low is 25°F. From 1991 to 2020 the coldest December reading was -7°F (December 9, 2013).
Does it rain a lot in Boise in December?
About 12 days in December have at least 0.01 in of precipitation, and the normal total is 1.5 in. The wettest December in 1991-2020 was in 1996 (3.4 in); the driest was in 1991 (0.4 in).
Does it snow in Boise in December?
Yes. Normal snowfall in December is 5.6 in, and snow covers the ground on about 6 days.
Is December a good time to visit Boise?
December ranks 12th of 12 months on our comfort score for Boise (30 out of 100). It has almost no comfortable days. The best month is May.
Where the numbers come from
- Temperature, rain, snowfall, snow depth, frost dates, humidity and wind by hour and cloud cover: Boise Air Terminal (USW00024131), 3.7 mi SSW of the city center, 2,814 ft (114 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Boise Air Terminal/Gowen Fd Airport (726810-24131), 3.7 mi SSW of the city center, 2,823 ft (123 ft higher than the city). Hourly observations, 1991-2020.