S
M
T
W
T
F
S
30
85°
63°
31
86°
63°
1
88°
65°
2
89°
66°
3
90°
65°
4
88°
64°
5
83°
63°
6
83°
59°
7
84°
60°
8
83°
63°
9
86°
63°
10
87°
65°
11
88°
63°
12
86°
62°
13
86°
61°
14
86°
62°
15
86°
62°
16
78°
57°
17
79°
61°
18
Hist. Avg.
82°
58°
19
Hist. Avg.
81°
58°
20
Hist. Avg.
81°
57°
21
Hist. Avg.
81°
57°
22
Hist. Avg.
80°
56°
23
Hist. Avg.
80°
56°
24
Hist. Avg.
80°
56°
25
Hist. Avg.
79°
55°
26
Hist. Avg.
79°
55°
27
Hist. Avg.
79°
55°
28
Hist. Avg.
78°
54°
29
Hist. Avg.
78°
54°
30
Hist. Avg.
78°
53°
1
Hist. Avg.
77°
53°
2
Hist. Avg.
77°
53°
3
Hist. Avg.
76°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Neptune
Neptune's September 2026 forecast shows daily high temperatures ranging from 78° to 90°, with overnight lows between 57° and 66°. The average high for September is 85° with an average low of 62°. 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 Neptune. See also: October | November | December.
