S
M
T
W
T
F
S
30
69°
49°
31
68°
48°
1
68°
49°
2
69°
51°
3
70°
50°
4
67°
51°
5
67°
50°
6
65°
52°
7
65°
48°
8
66°
47°
9
66°
48°
10
68°
48°
11
63°
46°
12
69°
45°
13
67°
49°
14
72°
52°
15
67°
53°
16
71°
52°
17
70°
51°
18
69°
47°
19
71°
51°
20
71°
47°
21
70°
48°
22
66°
48°
23
62°
42°
24
61°
41°
25
59°
43°
26
65°
40°
27
65°
40°
28
57°
39°
29
56°
40°
30
57°
42°
1
58°
42°
2
Hist. Avg.
60°
42°
3
Hist. Avg.
60°
42°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Stittsville
Stittsville's September 2026 forecast shows daily high temperatures ranging from 56° to 72°, with overnight lows between 39° and 53°. The average high for September is 66° with an average low of 47°. 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 Stittsville. See also: October | November | December.
