S
M
T
W
T
F
S
30
92°
72°
31
95°
70°
1
98°
71°
2
98°
72°
3
99°
73°
4
97°
72°
5
100°
74°
6
98°
71°
7
85°
72°
8
91°
67°
9
92°
65°
10
95°
72°
11
96°
72°
12
85°
73°
13
94°
73°
14
96°
68°
15
87°
70°
16
89°
68°
17
93°
63°
18
97°
67°
19
93°
70°
20
90°
73°
21
94°
70°
22
88°
71°
23
73°
64°
24
67°
60°
25
N/A
26
83°
51°
27
N/A
28
85°
51°
29
88°
55°
30
89°
58°
1
89°
61°
2
91°
64°
3
84°
71°
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 ° 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.
