S
M
T
W
T
F
S
29
40°
33°
30
40°
33°
1
45°
32°
2
44°
33°
3
46°
32°
4
33°
26°
5
44°
22°
6
44°
19°
7
32°
16°
8
30°
22°
9
34°
20°
10
33°
18°
11
33°
19°
12
34°
19°
13
35°
23°
14
34°
24°
15
36°
28°
16
37°
24°
17
41°
21°
18
35°
21°
19
31°
19°
20
32°
19°
21
32°
18°
22
31°
23°
23
35°
24°
24
38°
26°
25
38°
26°
26
35°
23°
27
34°
22°
28
31°
17°
29
29°
12°
30
28°
12°
31
28°
13°
1
30°
11°
2
31°
15°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in South Lyon
South Lyon's December 2026 forecast shows daily high temperatures ranging from 28° to 46°, with overnight lows between 11° and 33°. The average high for December is 35° with an average low of 22°. 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 South Lyon. See also: January | February | March.
