S
M
T
W
T
F
S
30
61°
45°
31
66°
48°
1
69°
47°
2
68°
47°
3
68°
48°
4
70°
48°
5
70°
45°
6
60°
40°
7
59°
46°
8
66°
43°
9
58°
45°
10
63°
38°
11
58°
38°
12
57°
37°
13
56°
37°
14
55°
36°
15
53°
35°
16
Hist. Avg.
58°
38°
17
Hist. Avg.
58°
38°
18
Hist. Avg.
58°
38°
19
Hist. Avg.
58°
38°
20
Hist. Avg.
57°
38°
21
Hist. Avg.
57°
37°
22
Hist. Avg.
57°
37°
23
Hist. Avg.
57°
37°
24
Hist. Avg.
56°
37°
25
Hist. Avg.
56°
36°
26
Hist. Avg.
56°
36°
27
Hist. Avg.
56°
36°
28
Hist. Avg.
56°
36°
29
Hist. Avg.
55°
36°
30
Hist. Avg.
55°
35°
1
Hist. Avg.
55°
35°
2
Hist. Avg.
54°
35°
3
Hist. Avg.
54°
35°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Slave Lake
Slave Lake's September 2026 forecast shows daily high temperatures ranging from 53° to 70°, with overnight lows between 35° and 48°. The average high for September is 62° with an average low of 43°. 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 Slave Lake. See also: October | November | December.
