S
M
T
W
T
F
S
30
82°
62°
31
85°
63°
1
85°
61°
2
84°
59°
3
82°
62°
4
80°
61°
5
81°
60°
6
78°
60°
7
78°
59°
8
80°
53°
9
78°
53°
10
77°
61°
11
82°
59°
12
81°
58°
13
82°
59°
14
81°
57°
15
82°
58°
16
Hist. Avg.
78°
55°
17
Hist. Avg.
78°
55°
18
Hist. Avg.
78°
54°
19
Hist. Avg.
77°
54°
20
Hist. Avg.
77°
53°
21
Hist. Avg.
76°
53°
22
Hist. Avg.
76°
52°
23
Hist. Avg.
76°
52°
24
Hist. Avg.
75°
51°
25
Hist. Avg.
75°
51°
26
Hist. Avg.
74°
50°
27
Hist. Avg.
74°
50°
28
Hist. Avg.
74°
50°
29
Hist. Avg.
73°
49°
30
Hist. Avg.
73°
49°
1
Hist. Avg.
72°
48°
2
Hist. Avg.
72°
48°
3
Hist. Avg.
71°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Potomac
Potomac's September 2026 forecast shows daily high temperatures ranging from 77° to 85°, with overnight lows between 53° and 63°. The average high for September is 81° 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 Potomac. See also: October | November | December.
