S
M
T
W
T
F
S
30
76°
38°
31
88°
39°
1
83°
49°
2
75°
53°
3
63°
42°
4
65°
37°
5
69°
44°
6
65°
46°
7
68°
50°
8
76°
41°
9
85°
40°
10
89°
41°
11
75°
51°
12
85°
39°
13
59°
48°
14
67°
38°
15
71°
47°
16
74°
45°
17
74°
51°
18
73°
46°
19
74°
44°
20
78°
47°
21
83°
48°
22
79°
47°
23
76°
48°
24
76°
46°
25
74°
47°
26
76°
48°
27
66°
40°
28
64°
36°
29
65°
41°
30
64°
42°
1
63°
39°
2
68°
40°
3
61°
34°
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 61° to 83°, with overnight lows between 34° and 51°. The average high for September is 71° 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 La Grande. See also: October | November | December.
