S
M
T
W
T
F
S
30
77°
58°
31
77°
58°
1
78°
61°
2
77°
60°
3
77°
59°
4
78°
64°
5
76°
64°
6
80°
65°
7
83°
65°
8
82°
64°
9
79°
63°
10
79°
63°
11
78°
64°
12
77°
63°
13
79°
62°
14
72°
62°
15
72°
60°
16
73°
58°
17
71°
57°
18
75°
60°
19
74°
59°
20
74°
57°
21
81°
59°
22
81°
52°
23
78°
51°
24
70°
50°
25
69°
56°
26
68°
58°
27
75°
58°
28
76°
56°
29
77°
54°
30
76°
53°
1
75°
56°
2
74°
56°
3
76°
57°
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 68° to 83°, with overnight lows between 50° and 65°. The average high for September is 76° with an average low of 59°. 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.
