S
M
T
W
T
F
S
30
75°
54°
31
78°
59°
1
74°
60°
2
81°
52°
3
74°
49°
4
71°
50°
5
71°
49°
6
72°
54°
7
78°
57°
8
80°
58°
9
80°
56°
10
77°
51°
11
72°
56°
12
73°
52°
13
76°
48°
14
71°
48°
15
69°
46°
16
70°
47°
17
73°
54°
18
76°
44°
19
69°
49°
20
69°
44°
21
70°
50°
22
68°
52°
23
75°
54°
24
77°
53°
25
74°
53°
26
74°
52°
27
73°
52°
28
76°
49°
29
73°
51°
30
72°
52°
1
75°
48°
2
74°
41°
3
71°
40°
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 68° to 81°, with overnight lows between 40° and 60°. The average high for September is 74° with an average low of 51°. 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.
