S
M
T
W
T
F
S
30
61°
33°
31
56°
35°
1
55°
33°
2
57°
39°
3
60°
40°
4
63°
37°
5
59°
37°
6
59°
35°
7
56°
34°
8
54°
38°
9
58°
27°
10
59°
32°
11
52°
36°
12
52°
37°
13
54°
38°
14
57°
36°
15
56°
33°
16
53°
30°
17
48°
28°
18
47°
30°
19
46°
33°
20
50°
32°
21
49°
31°
22
45°
30°
23
45°
31°
24
Hist. Avg.
48°
32°
25
Hist. Avg.
47°
32°
26
Hist. Avg.
46°
31°
27
Hist. Avg.
46°
30°
28
Hist. Avg.
45°
30°
29
Hist. Avg.
44°
29°
30
Hist. Avg.
44°
29°
1
Hist. Avg.
43°
28°
2
Hist. Avg.
42°
28°
3
Hist. Avg.
41°
27°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Richardson
Richardson's September 2026 forecast shows daily high temperatures ranging from 45° to 63°, with overnight lows between 27° and 40°. The average high for September is 54° with an average low of 34°. 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 Richardson. See also: October | November | December.
