S
M
T
W
T
F
S
30
77°
53°
31
77°
56°
1
76°
53°
2
76°
53°
3
75°
56°
4
76°
51°
5
69°
51°
6
73°
53°
7
74°
54°
8
73°
53°
9
68°
52°
10
66°
50°
11
66°
47°
12
67°
47°
13
65°
46°
14
65°
46°
15
66°
47°
16
67°
45°
17
70°
44°
18
63°
44°
19
64°
46°
20
63°
45°
21
63°
44°
22
64°
45°
23
62°
46°
24
63°
45°
25
62°
45°
26
62°
44°
27
62°
49°
28
61°
50°
29
Hist. Avg.
65°
49°
30
Hist. Avg.
65°
49°
1
Hist. Avg.
64°
49°
2
Hist. Avg.
64°
48°
3
Hist. Avg.
63°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Rheinfelden
Rheinfelden's September 2026 forecast shows daily high temperatures ranging from 61° to 77°, with overnight lows between 44° and 56°. The average high for September is 68° with an average low of 49°. 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 Rheinfelden. See also: October | November | December.
