S
M
T
W
T
F
S
30
86°
61°
31
89°
61°
1
90°
64°
2
90°
63°
3
88°
64°
4
89°
63°
5
89°
63°
6
88°
64°
7
89°
59°
8
85°
63°
9
89°
63°
10
87°
62°
11
86°
62°
12
88°
61°
13
88°
56°
14
82°
55°
15
81°
55°
16
81°
56°
17
82°
59°
18
86°
60°
19
86°
59°
20
85°
60°
21
80°
59°
22
84°
58°
23
85°
58°
24
84°
52°
25
78°
51°
26
77°
50°
27
Hist. Avg.
83°
59°
28
Hist. Avg.
82°
59°
29
Hist. Avg.
82°
59°
30
Hist. Avg.
82°
58°
1
Hist. Avg.
82°
58°
2
Hist. Avg.
81°
57°
3
Hist. Avg.
81°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Smithsonia
Smithsonia's September 2026 forecast shows daily high temperatures ranging from 77° to 90°, with overnight lows between 50° and 64°. The average high for September is 85° with an average low of 59°. 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 Smithsonia. See also: October | November | December.
