S
M
T
W
T
F
S
30
73°
58°
31
74°
57°
1
76°
50°
2
73°
50°
3
73°
51°
4
74°
49°
5
73°
49°
6
74°
56°
7
78°
55°
8
72°
55°
9
75°
54°
10
78°
54°
11
77°
55°
12
77°
54°
13
76°
55°
14
78°
54°
15
77°
50°
16
76°
47°
17
70°
52°
18
67°
54°
19
76°
53°
20
74°
52°
21
75°
44°
22
74°
43°
23
71°
49°
24
67°
51°
25
68°
50°
26
Hist. Avg.
66°
42°
27
Hist. Avg.
65°
42°
28
Hist. Avg.
65°
42°
29
Hist. Avg.
65°
41°
30
Hist. Avg.
64°
41°
1
Hist. Avg.
64°
40°
2
Hist. Avg.
64°
40°
3
Hist. Avg.
63°
40°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Northwest
Northwest's September 2026 forecast shows daily high temperatures ranging from 67° to 78°, with overnight lows between 43° and 58°. The average high for September is 74° with an average low of 52°. 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 Northwest. See also: October | November | December.
