S
M
T
W
T
F
S
30
105°
77°
31
103°
73°
1
102°
72°
2
102°
75°
3
100°
73°
4
100°
73°
5
102°
75°
6
105°
73°
7
104°
79°
8
105°
79°
9
108°
70°
10
92°
68°
11
99°
71°
12
102°
71°
13
97°
64°
14
87°
60°
15
83°
59°
16
87°
61°
17
88°
63°
18
85°
61°
19
86°
59°
20
83°
56°
21
88°
63°
22
87°
62°
23
88°
62°
24
82°
61°
25
75°
61°
26
80°
60°
27
80°
61°
28
81°
61°
29
78°
60°
30
83°
50°
1
70°
46°
2
70°
47°
3
69°
46°
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 69° to 108°, with overnight lows between 46° and 79°. The average high for September is 87° with an average low of 62°. 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.
