S
M
T
W
T
F
S
30
77°
45°
31
81°
49°
1
85°
55°
2
88°
56°
3
89°
49°
4
81°
44°
5
75°
48°
6
77°
49°
7
77°
48°
8
79°
47°
9
79°
51°
10
80°
44°
11
76°
44°
12
77°
45°
13
77°
45°
14
79°
40°
15
71°
38°
16
71°
37°
17
72°
39°
18
71°
40°
19
74°
47°
20
81°
43°
21
81°
42°
22
78°
39°
23
70°
38°
24
67°
37°
25
65°
38°
26
66°
35°
27
66°
37°
28
67°
39°
29
70°
41°
30
68°
34°
1
64°
37°
2
Hist. Avg.
70°
40°
3
Hist. Avg.
69°
39°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in La Grande
La Grande's September 2026 forecast shows daily high temperatures ranging from 64° to 89°, with overnight lows between 34° and 56°. The average high for September is 75° with an average low of 43°. 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 La Grande. See also: October | November | December.
