S
M
T
W
T
F
S
30
74°
51°
31
70°
54°
1
68°
58°
2
70°
52°
3
74°
52°
4
77°
53°
5
76°
49°
6
71°
49°
7
69°
50°
8
67°
61°
9
66°
54°
10
62°
47°
11
71°
47°
12
66°
54°
13
63°
40°
14
62°
35°
15
62°
50°
16
62°
46°
17
63°
43°
18
57°
34°
19
60°
40°
20
60°
37°
21
60°
32°
22
61°
32°
23
64°
34°
24
63°
35°
25
63°
47°
26
68°
49°
27
64°
50°
28
64°
52°
29
61°
53°
30
62°
49°
1
61°
44°
2
59°
42°
3
61°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Marathon
Marathon's September 2026 forecast shows daily high temperatures ranging from 59° to 68°, with overnight lows between 42° and 53°. The average high for September is 63° with an average low of 48°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how September weather will actually feel in Marathon. See also: October | November | December.
