S
M
T
W
T
F
S
30
74°
47°
31
71°
41°
1
74°
41°
2
74°
49°
3
71°
56°
4
71°
57°
5
64°
52°
6
68°
45°
7
75°
44°
8
67°
42°
9
71°
40°
10
71°
52°
11
62°
45°
12
75°
41°
13
73°
53°
14
63°
45°
15
67°
38°
16
72°
55°
17
70°
51°
18
63°
41°
19
58°
35°
20
59°
39°
21
58°
37°
22
63°
34°
23
65°
31°
24
71°
31°
25
71°
46°
26
69°
48°
27
63°
46°
28
56°
46°
29
57°
45°
30
62°
53°
1
66°
51°
2
64°
46°
3
62°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Thetford Mines
Thetford Mines's September 2026 forecast shows daily high temperatures ranging from 56° to 71°, with overnight lows between 44° and 53°. The average high for September is 63° 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 Thetford Mines. See also: October | November | December.
