S
M
T
W
T
F
S
30
80°
59°
31
80°
68°
1
84°
66°
2
69°
64°
3
87°
67°
4
85°
71°
5
79°
66°
6
77°
60°
7
79°
55°
8
80°
56°
9
84°
60°
10
86°
69°
11
80°
60°
12
80°
55°
13
81°
65°
14
75°
55°
15
74°
50°
16
81°
55°
17
82°
67°
18
82°
65°
19
71°
61°
20
68°
61°
21
72°
59°
22
68°
56°
23
67°
53°
24
66°
50°
25
69°
53°
26
63°
56°
27
62°
57°
28
64°
58°
29
70°
55°
30
77°
63°
1
79°
64°
2
84°
56°
3
72°
52°
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 70° to 84°, with overnight lows between 52° and 64°. The average high for September is 76° with an average low of 58°. 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.
