S
M
T
W
T
F
S
29
54°
38°
30
56°
35°
1
54°
28°
2
51°
23°
3
42°
26°
4
43°
32°
5
46°
27°
6
45°
25°
7
41°
32°
8
47°
27°
9
49°
24°
10
41°
20°
11
37°
18°
12
35°
19°
13
34°
18°
14
36°
16°
15
35°
16°
16
32°
17°
17
34°
15°
18
36°
13°
19
35°
13°
20
32°
21°
21
35°
25°
22
38°
27°
23
40°
27°
24
38°
28°
25
47°
27°
26
47°
23°
27
36°
23°
28
35°
15°
29
Hist. Avg.
40°
24°
30
Hist. Avg.
40°
24°
31
Hist. Avg.
40°
24°
1
Hist. Avg.
39°
24°
2
Hist. Avg.
39°
24°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Lehigh Valley
Lehigh Valley's December 2026 forecast shows daily high temperatures ranging from 32° to 56°, with overnight lows between 13° and 38°. The average high for December is 41° with an average low of 23°. 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 Lehigh Valley. See also: January | February | March.
