S
M
T
W
T
F
S
30
74°
52°
31
74°
51°
1
75°
55°
2
75°
60°
3
74°
61°
4
82°
61°
5
83°
60°
6
82°
52°
7
79°
51°
8
74°
51°
9
75°
50°
10
73°
53°
11
73°
55°
12
71°
50°
13
75°
54°
14
78°
56°
15
78°
54°
16
72°
55°
17
71°
54°
18
73°
53°
19
76°
47°
20
72°
49°
21
73°
46°
22
75°
45°
23
68°
45°
24
67°
46°
25
67°
48°
26
68°
44°
27
67°
44°
28
66°
46°
29
64°
42°
30
65°
42°
1
64°
47°
2
71°
42°
3
68°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Fitchburg
Fitchburg's September 2026 forecast shows daily high temperatures ranging from 64° to 83°, with overnight lows between 42° and 61°. The average high for September is 73° with an average low of 50°. 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 Fitchburg. See also: October | November | December.
