S
M
T
W
T
F
S
30
81°
67°
31
82°
68°
1
86°
71°
2
85°
69°
3
84°
68°
4
81°
66°
5
78°
61°
6
79°
61°
7
81°
64°
8
81°
65°
9
82°
66°
10
81°
61°
11
82°
55°
12
73°
56°
13
75°
55°
14
78°
57°
15
72°
56°
16
72°
61°
17
74°
54°
18
70°
52°
19
70°
52°
20
71°
55°
21
75°
59°
22
78°
60°
23
79°
60°
24
78°
57°
25
76°
55°
26
76°
56°
27
77°
58°
28
76°
57°
29
75°
54°
30
69°
50°
1
65°
48°
2
68°
53°
3
73°
56°
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 65° to 86°, with overnight lows between 48° and 71°. The average high for September is 77° 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.
