S
M
T
W
T
F
S
30
93°
72°
31
94°
73°
1
93°
71°
2
93°
70°
3
94°
69°
4
94°
70°
5
95°
71°
6
95°
71°
7
94°
72°
8
95°
71°
9
95°
69°
10
94°
66°
11
92°
67°
12
93°
66°
13
90°
65°
14
89°
64°
15
88°
63°
16
88°
65°
17
92°
64°
18
93°
68°
19
89°
69°
20
92°
67°
21
88°
64°
22
86°
62°
23
Hist. Avg.
88°
65°
24
Hist. Avg.
88°
65°
25
Hist. Avg.
88°
64°
26
Hist. Avg.
87°
64°
27
Hist. Avg.
87°
64°
28
Hist. Avg.
87°
64°
29
Hist. Avg.
86°
63°
30
Hist. Avg.
86°
63°
1
Hist. Avg.
86°
63°
2
Hist. Avg.
86°
62°
3
Hist. Avg.
85°
62°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Washington
Washington's September 2026 forecast shows daily high temperatures ranging from 86° to 95°, with overnight lows between 62° and 73°. The average high for September is 92° with an average low of 68°. 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 Washington. See also: October | November | December.
