S
M
T
W
T
F
S
30
92°
69°
31
94°
71°
1
94°
73°
2
95°
73°
3
95°
73°
4
90°
72°
5
94°
73°
6
95°
74°
7
97°
73°
8
95°
71°
9
94°
71°
10
90°
71°
11
93°
73°
12
95°
73°
13
95°
73°
14
97°
74°
15
94°
73°
16
96°
74°
17
93°
70°
18
94°
65°
19
94°
67°
20
100°
71°
21
96°
72°
22
95°
75°
23
93°
70°
24
83°
65°
25
88°
60°
26
87°
62°
27
90°
62°
28
91°
62°
29
92°
63°
30
94°
69°
1
93°
73°
2
92°
72°
3
91°
71°
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.
