S
M
T
W
T
F
S
30
81°
49°
31
82°
51°
1
84°
52°
2
86°
56°
3
88°
56°
4
91°
58°
5
91°
53°
6
87°
50°
7
84°
54°
8
88°
49°
9
77°
44°
10
75°
50°
11
77°
54°
12
81°
56°
13
78°
55°
14
76°
45°
15
75°
44°
16
79°
42°
17
74°
42°
18
Hist. Avg.
80°
46°
19
Hist. Avg.
80°
46°
20
Hist. Avg.
79°
45°
21
Hist. Avg.
79°
45°
22
Hist. Avg.
79°
44°
23
Hist. Avg.
78°
44°
24
Hist. Avg.
78°
44°
25
Hist. Avg.
77°
44°
26
Hist. Avg.
77°
43°
27
Hist. Avg.
76°
43°
28
Hist. Avg.
76°
42°
29
Hist. Avg.
75°
42°
30
Hist. Avg.
75°
42°
1
Hist. Avg.
74°
42°
2
Hist. Avg.
74°
41°
3
Hist. Avg.
74°
41°
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 74° to 91°, with overnight lows between 42° and 58°. The average high for September is 82° with an average low of 51°. 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.
