S
M
T
W
T
F
S
30
69°
49°
31
68°
48°
1
69°
48°
2
69°
50°
3
70°
50°
4
67°
51°
5
68°
49°
6
67°
52°
7
66°
47°
8
67°
46°
9
67°
48°
10
68°
48°
11
64°
46°
12
70°
44°
13
67°
49°
14
72°
52°
15
68°
52°
16
71°
51°
17
71°
51°
18
69°
47°
19
72°
51°
20
72°
47°
21
70°
48°
22
67°
47°
23
62°
42°
24
61°
41°
25
60°
43°
26
65°
40°
27
66°
39°
28
57°
40°
29
56°
40°
30
56°
37°
1
Hist. Avg.
61°
43°
2
Hist. Avg.
60°
42°
3
Hist. Avg.
60°
42°
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 56° to 72°, with overnight lows between 37° and 52°. The average high for September is 67° with an average low of 47°. 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.
