S
M
T
W
T
F
S
30
95°
72°
31
94°
73°
1
84°
76°
2
91°
76°
3
94°
74°
4
92°
73°
5
92°
72°
6
91°
72°
7
93°
74°
8
94°
72°
9
93°
74°
10
93°
73°
11
90°
72°
12
94°
73°
13
95°
72°
14
95°
73°
15
95°
73°
16
94°
73°
17
93°
69°
18
92°
64°
19
94°
65°
20
95°
68°
21
96°
70°
22
96°
72°
23
95°
70°
24
89°
67°
25
90°
63°
26
90°
63°
27
92°
63°
28
94°
66°
29
93°
66°
30
93°
67°
1
89°
73°
2
93°
73°
3
88°
74°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Washington
Washington's September 2026 forecast shows daily high temperatures ranging from ° to °, with overnight lows between ° and °. The average high for September is ° with an average low of °. 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.
