S
M
T
W
T
F
S
30
85°
62°
31
85°
63°
1
84°
61°
2
84°
61°
3
83°
62°
4
84°
62°
5
83°
61°
6
83°
60°
7
84°
60°
8
Hist. Avg.
85°
62°
9
Hist. Avg.
85°
61°
10
Hist. Avg.
85°
61°
11
Hist. Avg.
84°
61°
12
Hist. Avg.
84°
60°
13
Hist. Avg.
84°
60°
14
Hist. Avg.
83°
60°
15
Hist. Avg.
83°
59°
16
Hist. Avg.
83°
59°
17
Hist. Avg.
82°
59°
18
Hist. Avg.
82°
58°
19
Hist. Avg.
82°
58°
20
Hist. Avg.
81°
58°
21
Hist. Avg.
81°
57°
22
Hist. Avg.
81°
57°
23
Hist. Avg.
80°
56°
24
Hist. Avg.
80°
56°
25
Hist. Avg.
80°
56°
26
Hist. Avg.
79°
55°
27
Hist. Avg.
79°
55°
28
Hist. Avg.
78°
54°
29
Hist. Avg.
78°
54°
30
Hist. Avg.
78°
53°
1
Hist. Avg.
78°
53°
2
Hist. Avg.
77°
52°
3
Hist. Avg.
77°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Markham
Markham's September 2026 forecast shows daily high temperatures ranging from 83° to 85°, with overnight lows between 60° and 63°. The average high for September is 84° with an average low of 61°. 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 Markham. See also: October | November | December.
