S
M
T
W
T
F
S
30
88°
50°
31
76°
47°
1
72°
47°
2
79°
54°
3
81°
57°
4
78°
49°
5
79°
47°
6
80°
52°
7
85°
53°
8
84°
55°
9
86°
56°
10
86°
54°
11
89°
54°
12
88°
53°
13
86°
55°
14
85°
51°
15
87°
54°
16
86°
55°
17
87°
54°
18
84°
53°
19
81°
53°
20
86°
54°
21
86°
54°
22
85°
53°
23
83°
53°
24
82°
48°
25
77°
48°
26
78°
49°
27
76°
46°
28
78°
51°
29
82°
52°
30
81°
51°
1
77°
51°
2
82°
50°
3
84°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Atascadero
Atascadero's September 2026 forecast shows daily high temperatures ranging from 72° to 89°, with overnight lows between 46° and 57°. The average high for September is 82° with an average low of 52°. 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 Atascadero. See also: October | November | December.
