S
M
T
W
T
F
S
29
70°
48°
30
64°
44°
1
65°
46°
2
64°
47°
3
64°
44°
4
65°
46°
5
65°
44°
6
67°
44°
7
70°
46°
8
66°
46°
9
62°
42°
10
61°
46°
11
63°
36°
12
61°
37°
13
62°
42°
14
67°
41°
15
70°
43°
16
69°
39°
17
62°
45°
18
64°
44°
19
64°
47°
20
66°
48°
21
68°
36°
22
66°
35°
23
61°
36°
24
60°
38°
25
61°
41°
26
63°
42°
27
63°
41°
28
62°
38°
29
61°
38°
30
61°
37°
31
60°
36°
1
60°
38°
2
61°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Upland
Upland's December 2026 forecast shows daily high temperatures ranging from 60° to 70°, with overnight lows between 35° and 48°. The average high for December is 64° with an average low of 42°. 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 Upland. See also: January | February | March.
