S
M
T
W
T
F
S
29
33°
24°
30
39°
24°
1
42°
23°
2
40°
20°
3
31°
18°
4
33°
23°
5
36°
15°
6
28°
12°
7
28°
12°
8
34°
23°
9
39°
22°
10
35°
21°
11
38°
22°
12
39°
21°
13
34°
17°
14
31°
6°
15
25°
5°
16
25°
11°
17
31°
18°
18
34°
19°
19
38°
19°
20
36°
18°
21
38°
18°
22
37°
16°
23
28°
14°
24
34°
19°
25
25°
0°
26
24°
1°
27
24°
1°
28
25°
14°
29
29°
16°
30
36°
14°
31
35°
15°
1
33°
13°
2
35°
6°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Bethlehem
Bethlehem's December 2026 forecast shows daily high temperatures ranging from 24° to 42°, with overnight lows between 0° and 24°. The average high for December is 33° with an average low of 15°. 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 Bethlehem. See also: January | February | March.