S
M
T
W
T
F
S
30
76°
52°
31
80°
55°
1
82°
50°
2
76°
49°
3
75°
51°
4
79°
57°
5
80°
57°
6
82°
55°
7
77°
55°
8
75°
54°
9
78°
55°
10
80°
54°
11
74°
54°
12
77°
55°
13
75°
51°
14
72°
45°
15
70°
46°
16
71°
45°
17
71°
51°
18
75°
51°
19
77°
52°
20
78°
53°
21
71°
46°
22
75°
49°
23
69°
51°
24
75°
45°
25
72°
41°
26
67°
41°
27
Hist. Avg.
74°
48°
28
Hist. Avg.
74°
48°
29
Hist. Avg.
74°
47°
30
Hist. Avg.
73°
47°
1
Hist. Avg.
73°
47°
2
Hist. Avg.
72°
46°
3
Hist. Avg.
72°
46°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Mercer
Mercer's September 2026 forecast shows daily high temperatures ranging from 67° to 82°, with overnight lows between 41° and 57°. The average high for September is 75° with an average low of 51°. 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 Mercer. See also: October | November | December.
