S
M
T
W
T
F
S
29
38°
23°
30
36°
22°
1
37°
32°
2
41°
33°
3
36°
31°
4
38°
24°
5
35°
22°
6
35°
21°
7
36°
22°
8
36°
24°
9
37°
21°
10
37°
24°
11
42°
22°
12
40°
24°
13
43°
29°
14
37°
31°
15
37°
22°
16
39°
28°
17
34°
24°
18
38°
25°
19
40°
29°
20
41°
22°
21
37°
22°
22
36°
28°
23
37°
21°
24
38°
30°
25
36°
27°
26
41°
17°
27
38°
16°
28
28°
25°
29
32°
17°
30
35°
27°
31
32°
27°
1
37°
29°
2
37°
22°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Boise
Boise's December 2026 forecast shows daily high temperatures ranging from 28° to 43°, with overnight lows between 16° and 33°. The average high for December is 37° with an average low of 25°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how December weather will actually feel in Boise. See also: January | February | March.
