S
M
T
W
T
F
S
30
80°
53°
31
76°
52°
1
74°
52°
2
74°
51°
3
75°
57°
4
73°
52°
5
77°
50°
6
73°
49°
7
72°
50°
8
73°
51°
9
73°
52°
10
76°
56°
11
77°
55°
12
70°
54°
13
69°
56°
14
77°
55°
15
Hist. Avg.
71°
49°
16
Hist. Avg.
70°
49°
17
Hist. Avg.
70°
48°
18
Hist. Avg.
70°
48°
19
Hist. Avg.
69°
48°
20
Hist. Avg.
69°
48°
21
Hist. Avg.
68°
47°
22
Hist. Avg.
68°
47°
23
Hist. Avg.
68°
46°
24
Hist. Avg.
67°
46°
25
Hist. Avg.
67°
46°
26
Hist. Avg.
66°
45°
27
Hist. Avg.
66°
45°
28
Hist. Avg.
66°
45°
29
Hist. Avg.
65°
44°
30
Hist. Avg.
65°
44°
1
Hist. Avg.
64°
44°
2
Hist. Avg.
64°
43°
3
Hist. Avg.
64°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mill River
Mill River's September 2026 forecast shows daily high temperatures ranging from 69° to 80°, with overnight lows between 49° and 57°. The average high for September is 74° with an average low of 53°. 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 Mill River. See also: October | November | December.