S
M
T
W
T
F
S
30
82°
56°
31
82°
45°
1
79°
44°
2
68°
42°
3
67°
44°
4
68°
45°
5
68°
45°
6
74°
53°
7
78°
46°
8
79°
43°
9
73°
45°
10
70°
43°
11
68°
49°
12
72°
42°
13
68°
38°
14
64°
45°
15
67°
51°
16
73°
45°
17
67°
41°
18
65°
49°
19
73°
41°
20
69°
36°
21
62°
41°
22
61°
51°
23
72°
38°
24
73°
39°
25
68°
42°
26
60°
46°
27
62°
42°
28
67°
47°
29
65°
48°
30
69°
37°
1
69°
35°
2
59°
35°
3
55°
36°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Grand Forks
Grand Forks's September 2026 forecast shows daily high temperatures ranging from 55° to 82°, with overnight lows between 35° and 56°. The average high for September is 69° with an average low of 44°. 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 Grand Forks. See also: October | November | December.
