S
M
T
W
T
F
S
29
67°
46°
30
67°
44°
1
69°
44°
2
69°
43°
3
64°
44°
4
67°
46°
5
69°
46°
6
70°
45°
7
71°
46°
8
70°
44°
9
64°
45°
10
63°
42°
11
63°
41°
12
63°
42°
13
Hist. Avg.
67°
41°
14
Hist. Avg.
66°
41°
15
Hist. Avg.
66°
41°
16
Hist. Avg.
66°
40°
17
Hist. Avg.
66°
40°
18
Hist. Avg.
66°
40°
19
Hist. Avg.
66°
40°
20
Hist. Avg.
66°
40°
21
Hist. Avg.
66°
40°
22
Hist. Avg.
66°
40°
23
Hist. Avg.
65°
40°
24
Hist. Avg.
65°
40°
25
Hist. Avg.
65°
40°
26
Hist. Avg.
65°
40°
27
Hist. Avg.
65°
40°
28
Hist. Avg.
65°
40°
29
Hist. Avg.
65°
40°
30
Hist. Avg.
65°
40°
31
Hist. Avg.
65°
40°
1
Hist. Avg.
68°
41°
2
Hist. Avg.
68°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
December Weather in Rialto
Rialto's December 2026 forecast shows daily high temperatures ranging from 63° to 71°, with overnight lows between 41° and 46°. The average high for December is 67° with an average low of 44°. 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 Rialto. See also: January | February | March.
