S
M
T
W
T
F
S
31
81°
58°
1
81°
57°
2
80°
60°
3
83°
60°
4
88°
65°
5
89°
65°
6
93°
66°
7
78°
61°
8
76°
57°
9
77°
56°
10
70°
61°
11
81°
66°
12
82°
63°
13
82°
62°
14
85°
65°
15
82°
66°
16
72°
61°
17
69°
62°
18
81°
65°
19
90°
65°
20
77°
68°
21
74°
65°
22
78°
62°
23
84°
65°
24
79°
68°
25
81°
72°
26
85°
69°
27
79°
67°
28
84°
67°
29
78°
66°
30
76°
67°
1
75°
59°
2
72°
55°
3
72°
55°
4
78°
55°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Washington
Washington's September 2025 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.
