S
M
T
W
T
F
S
30
81°
57°
31
79°
55°
1
77°
52°
2
81°
52°
3
81°
55°
4
88°
55°
5
81°
61°
6
82°
57°
7
84°
59°
8
91°
59°
9
72°
50°
10
70°
46°
11
73°
46°
12
77°
46°
13
77°
48°
14
79°
57°
15
81°
54°
16
73°
54°
17
70°
45°
18
72°
52°
19
75°
46°
20
79°
48°
21
75°
50°
22
75°
48°
23
73°
45°
24
N/A
25
74°
45°
26
80°
46°
27
80°
48°
28
81°
52°
29
81°
52°
30
79°
55°
1
76°
56°
2
72°
53°
3
72°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Grenchen
Grenchen's September 2026 forecast shows daily high temperatures ranging from 72° to 81°, with overnight lows between 45° and 56°. The average high for September is 77° 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 Grenchen. See also: October | November | December.
