S
M
T
W
T
F
S
30
88°
64°
31
89°
68°
1
88°
72°
2
93°
71°
3
94°
72°
4
91°
70°
5
85°
69°
6
82°
60°
7
84°
60°
8
86°
61°
9
87°
67°
10
78°
71°
11
81°
67°
12
85°
67°
13
84°
68°
14
74°
55°
15
85°
51°
16
90°
64°
17
86°
70°
18
82°
64°
19
83°
60°
20
78°
67°
21
76°
58°
22
65°
57°
23
67°
56°
24
69°
48°
25
72°
42°
26
73°
44°
27
N/A
28
71°
55°
29
75°
52°
30
78°
60°
1
85°
62°
2
76°
54°
3
68°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Caldwell
Caldwell's September 2026 forecast shows daily high temperatures ranging from 68° to 85°, with overnight lows between 52° and 62°. The average high for September is 76° with an average low of 56°. 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.
