S
M
T
W
T
F
S
29
44°
34°
30
42°
34°
1
42°
34°
2
43°
34°
3
45°
33°
4
43°
34°
5
45°
30°
6
44°
25°
7
44°
31°
8
46°
33°
9
43°
30°
10
42°
29°
11
30°
20°
12
31°
21°
13
34°
28°
14
39°
30°
15
42°
25°
16
39°
27°
17
39°
23°
18
38°
18°
19
35°
19°
20
38°
28°
21
39°
22°
22
41°
15°
23
31°
18°
24
28°
22°
25
31°
29°
26
34°
28°
27
36°
28°
28
38°
22°
29
36°
18°
30
35°
15°
31
30°
19°
1
29°
20°
2
32°
28°
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 46°, with overnight lows between 15° and 34°. The average high for December is 38° with an average low of 26°. 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.
