S
M
T
W
T
F
S
29
42°
22°
30
31°
18°
1
30°
19°
2
39°
26°
3
43°
26°
4
38°
25°
5
33°
24°
6
31°
13°
7
27°
10°
8
37°
25°
9
42°
24°
10
42°
23°
11
41°
24°
12
40°
23°
13
41°
24°
14
37°
20°
15
36°
21°
16
37°
15°
17
36°
11°
18
28°
5°
19
27°
6°
20
23°
21°
21
32°
17°
22
34°
12°
23
33°
16°
24
32°
15°
25
34°
21°
26
33°
20°
27
38°
7°
28
32°
6°
29
24°
13°
30
27°
5°
31
26°
7°
1
22°
18°
2
31°
21°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Newcastle
Newcastle's December 2026 forecast shows daily high temperatures ranging from 22° to 43°, with overnight lows between 5° and 26°. The average high for December is 34° with an average low of 17°. 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 Newcastle. See also: January | February | March.
