S
M
T
W
T
F
S
30
79°
51°
31
75°
48°
1
70°
49°
2
68°
45°
3
67°
51°
4
70°
53°
5
75°
51°
6
69°
46°
7
66°
44°
8
Hist. Avg.
71°
50°
9
Hist. Avg.
71°
50°
10
Hist. Avg.
70°
49°
11
Hist. Avg.
70°
49°
12
Hist. Avg.
70°
48°
13
Hist. Avg.
69°
48°
14
Hist. Avg.
69°
47°
15
Hist. Avg.
68°
47°
16
Hist. Avg.
68°
46°
17
Hist. Avg.
67°
46°
18
Hist. Avg.
67°
46°
19
Hist. Avg.
66°
45°
20
Hist. Avg.
66°
45°
21
Hist. Avg.
66°
44°
22
Hist. Avg.
65°
44°
23
Hist. Avg.
65°
43°
24
Hist. Avg.
64°
43°
25
Hist. Avg.
64°
42°
26
Hist. Avg.
63°
42°
27
Hist. Avg.
63°
42°
28
Hist. Avg.
62°
41°
29
Hist. Avg.
62°
41°
30
Hist. Avg.
61°
40°
1
Hist. Avg.
61°
40°
2
Hist. Avg.
60°
40°
3
Hist. Avg.
60°
39°
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 66° to 79°, with overnight lows between 44° and 53°. The average high for September is 71° with an average low of 49°. 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.
