S
M
T
W
T
F
S
30
68°
56°
31
79°
53°
1
73°
52°
2
76°
58°
3
70°
53°
4
70°
48°
5
74°
54°
6
76°
48°
7
68°
53°
8
75°
56°
9
77°
50°
10
73°
55°
11
70°
45°
12
75°
47°
13
67°
56°
14
65°
57°
15
73°
53°
16
78°
47°
17
76°
46°
18
73°
47°
19
72°
47°
20
76°
44°
21
72°
45°
22
71°
53°
23
62°
50°
24
62°
48°
25
60°
51°
26
64°
49°
27
67°
45°
28
64°
45°
29
58°
51°
30
65°
49°
1
62°
49°
2
66°
54°
3
74°
53°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Sumas
Sumas'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 Sumas. See also: October | November | December.
