S
M
T
W
T
F
S
30
79°
53°
31
72°
54°
1
73°
52°
2
72°
52°
3
72°
53°
4
73°
50°
5
71°
50°
6
70°
49°
7
70°
49°
8
71°
50°
9
70°
50°
10
73°
51°
11
75°
53°
12
75°
53°
13
74°
48°
14
69°
50°
15
68°
55°
16
69°
51°
17
67°
55°
18
73°
53°
19
74°
53°
20
73°
55°
21
74°
55°
22
73°
54°
23
73°
54°
24
68°
53°
25
67°
54°
26
70°
53°
27
66°
46°
28
62°
49°
29
61°
50°
30
68°
50°
1
67°
51°
2
70°
54°
3
61°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Heidelberg
Heidelberg's September 2026 forecast shows daily high temperatures ranging from 61° to 79°, with overnight lows between 44° and 55°. The average high for September is 70° with an average low of 52°. 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 Heidelberg. See also: October | November | December.
