S
M
T
W
T
F
S
30
61°
45°
31
55°
38°
1
N/A
2
64°
41°
3
63°
40°
4
63°
49°
5
60°
51°
6
60°
51°
7
61°
52°
8
58°
53°
9
57°
50°
10
55°
49°
11
56°
49°
12
53°
48°
13
51°
47°
14
54°
48°
15
54°
45°
16
52°
43°
17
49°
43°
18
49°
45°
19
49°
45°
20
50°
44°
21
49°
40°
22
48°
38°
23
47°
38°
24
48°
39°
25
47°
40°
26
46°
45°
27
47°
44°
28
50°
42°
29
48°
40°
30
48°
44°
1
47°
45°
2
48°
40°
3
48°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Whittier
Whittier's September 2026 forecast shows daily high temperatures ranging from 46° to 64°, with overnight lows between 38° and 53°. The average high for September is 52° with an average low of 45°. 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 Whittier. See also: October | November | December.