S
M
T
W
T
F
S
30
95°
65°
31
95°
66°
1
96°
66°
2
95°
67°
3
98°
65°
4
95°
63°
5
94°
61°
6
93°
60°
7
93°
61°
8
94°
62°
9
93°
61°
10
94°
60°
11
92°
61°
12
91°
61°
13
90°
62°
14
90°
65°
15
Hist. Avg.
93°
61°
16
Hist. Avg.
93°
61°
17
Hist. Avg.
92°
60°
18
Hist. Avg.
92°
60°
19
Hist. Avg.
91°
59°
20
Hist. Avg.
91°
59°
21
Hist. Avg.
91°
58°
22
Hist. Avg.
90°
58°
23
Hist. Avg.
90°
58°
24
Hist. Avg.
89°
57°
25
Hist. Avg.
89°
57°
26
Hist. Avg.
88°
56°
27
Hist. Avg.
88°
56°
28
Hist. Avg.
88°
55°
29
Hist. Avg.
87°
55°
30
Hist. Avg.
87°
54°
1
Hist. Avg.
86°
54°
2
Hist. Avg.
86°
54°
3
Hist. Avg.
85°
53°
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 90° to 98°, with overnight lows between 60° and 67°. The average high for September is 94° with an average low of 63°. 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.
