S
M
T
W
T
F
S
30
74°
55°
31
75°
50°
1
77°
48°
2
71°
47°
3
70°
49°
4
74°
57°
5
74°
53°
6
77°
47°
7
71°
48°
8
69°
54°
9
69°
54°
10
74°
53°
11
73°
54°
12
68°
54°
13
70°
51°
14
67°
46°
15
65°
44°
16
65°
44°
17
66°
53°
18
69°
52°
19
72°
53°
20
74°
52°
21
72°
47°
22
69°
45°
23
64°
43°
24
63°
42°
25
63°
41°
26
60°
42°
27
Hist. Avg.
65°
45°
28
Hist. Avg.
64°
45°
29
Hist. Avg.
64°
44°
30
Hist. Avg.
64°
44°
1
Hist. Avg.
63°
44°
2
Hist. Avg.
63°
43°
3
Hist. Avg.
62°
43°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in New Tecumseth
New Tecumseth's September 2026 forecast shows daily high temperatures ranging from 60° to 77°, with overnight lows between 41° and 57°. The average high for September is 70° with an average low of 49°. 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 New Tecumseth. See also: October | November | December.