S
M
T
W
T
F
S
30
81°
66°
31
90°
68°
1
92°
69°
2
91°
70°
3
91°
72°
4
91°
70°
5
88°
70°
6
81°
57°
7
81°
55°
8
84°
55°
9
79°
64°
10
79°
53°
11
82°
63°
12
86°
63°
13
82°
58°
14
84°
68°
15
86°
59°
16
74°
58°
17
72°
56°
18
71°
51°
19
74°
54°
20
71°
52°
21
70°
51°
22
70°
53°
23
75°
50°
24
78°
55°
25
73°
55°
26
78°
56°
27
78°
55°
28
77°
55°
29
77°
54°
30
76°
53°
1
75°
49°
2
69°
53°
3
75°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Rensselaer
Rensselaer's September 2026 forecast shows daily high temperatures ranging from 69° to 86°, with overnight lows between 49° and 68°. The average high for September is 76° with an average low of 55°. 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 Rensselaer. See also: October | November | December.
