S
M
T
W
T
F
S
29
80°
72°
30
82°
72°
1
83°
73°
2
83°
71°
3
82°
72°
4
83°
67°
5
82°
65°
6
79°
65°
7
74°
66°
8
74°
66°
9
78°
67°
10
77°
65°
11
75°
64°
12
74°
65°
13
74°
66°
14
76°
65°
15
75°
65°
16
74°
66°
17
74°
66°
18
75°
65°
19
75°
66°
20
76°
68°
21
76°
70°
22
77°
70°
23
80°
69°
24
79°
68°
25
78°
67°
26
79°
68°
27
78°
68°
28
79°
67°
29
79°
68°
30
80°
69°
31
80°
68°
1
79°
67°
2
79°
67°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Marathon
Marathon's December 2026 forecast shows daily high temperatures ranging from 74° to 83°, with overnight lows between 64° and 73°. The average high for December is 78° with an average low of 68°. 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 Marathon. See also: January | February | March.
