S
M
T
W
T
F
S
30
73°
56°
31
75°
54°
1
77°
61°
2
76°
63°
3
80°
61°
4
76°
56°
5
73°
55°
6
74°
55°
7
74°
54°
8
72°
55°
9
71°
59°
10
69°
54°
11
68°
52°
12
70°
51°
13
67°
54°
14
67°
50°
15
70°
55°
16
71°
53°
17
69°
48°
18
67°
50°
19
71°
50°
20
72°
53°
21
72°
53°
22
71°
52°
23
70°
50°
24
65°
49°
25
69°
51°
26
68°
50°
27
68°
49°
28
59°
47°
29
60°
47°
30
59°
45°
1
57°
42°
2
57°
43°
3
62°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Nepean
Nepean's September 2026 forecast shows daily high temperatures ranging from 57° to 80°, with overnight lows between 42° and 63°. The average high for September is 69° 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 Nepean. See also: October | November | December.
