S
M
T
W
T
F
S
30
91°
63°
31
82°
63°
1
75°
59°
2
78°
60°
3
71°
57°
4
77°
54°
5
82°
58°
6
83°
54°
7
86°
59°
8
92°
62°
9
95°
65°
10
90°
61°
11
96°
64°
12
93°
63°
13
92°
62°
14
91°
55°
15
94°
60°
16
91°
59°
17
92°
58°
18
92°
58°
19
86°
57°
20
87°
57°
21
91°
58°
22
92°
59°
23
89°
53°
24
82°
50°
25
80°
51°
26
79°
50°
27
80°
49°
28
80°
49°
29
82°
51°
30
81°
53°
1
79°
48°
2
80°
48°
3
83°
51°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Chico
Chico's September 2026 forecast shows daily high temperatures ranging from 71° to 96°, with overnight lows between 48° and 65°. The average high for September is 85° with an average low of 56°. 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 Chico. See also: October | November | December.