S
M
T
W
T
F
S
30
64°
54°
31
65°
54°
1
67°
53°
2
67°
53°
3
65°
54°
4
67°
54°
5
66°
51°
6
63°
53°
7
62°
52°
8
64°
50°
9
62°
50°
10
62°
51°
11
63°
48°
12
62°
51°
13
61°
48°
14
61°
51°
15
62°
50°
16
62°
49°
17
61°
50°
18
62°
49°
19
65°
48°
20
61°
46°
21
60°
50°
22
59°
47°
23
59°
45°
24
60°
46°
25
59°
49°
26
59°
50°
27
60°
47°
28
59°
46°
29
58°
45°
30
58°
44°
1
57°
45°
2
58°
50°
3
58°
45°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Caldwell
Caldwell's September 2026 forecast shows daily high temperatures ranging from 57° to 67°, with overnight lows between 44° and 54°. The average high for September is 62° with an average low of 49°. 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 Caldwell. See also: October | November | December.
