S
M
T
W
T
F
S
30
79°
30°
31
79°
37°
1
70°
46°
2
61°
48°
3
64°
46°
4
62°
44°
5
72°
45°
6
70°
40°
7
70°
40°
8
74°
45°
9
73°
47°
10
74°
46°
11
75°
45°
12
73°
45°
13
74°
44°
14
75°
45°
15
78°
40°
16
81°
44°
17
78°
44°
18
71°
40°
19
70°
37°
20
71°
39°
21
77°
43°
22
79°
43°
23
75°
42°
24
73°
39°
25
69°
38°
26
71°
40°
27
77°
42°
28
78°
42°
29
77°
41°
30
76°
41°
1
77°
42°
2
76°
42°
3
75°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Calpine
Calpine's September 2026 forecast shows daily high temperatures ranging from 61° to 81°, with overnight lows between 37° and 48°. The average high for September is 73° with an average low of 43°. 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 Calpine. See also: October | November | December.
