S
M
T
W
T
F
S
30
76°
53°
31
73°
53°
1
75°
49°
2
74°
46°
3
74°
48°
4
73°
50°
5
74°
51°
6
75°
51°
7
73°
44°
8
67°
43°
9
64°
45°
10
66°
50°
11
69°
43°
12
68°
50°
13
71°
49°
14
69°
50°
15
71°
51°
16
61°
47°
17
63°
48°
18
Hist. Avg.
65°
43°
19
Hist. Avg.
65°
43°
20
Hist. Avg.
64°
42°
21
Hist. Avg.
64°
42°
22
Hist. Avg.
64°
42°
23
Hist. Avg.
63°
41°
24
Hist. Avg.
63°
40°
25
Hist. Avg.
62°
40°
26
Hist. Avg.
62°
40°
27
Hist. Avg.
62°
39°
28
Hist. Avg.
61°
39°
29
Hist. Avg.
61°
38°
30
Hist. Avg.
60°
38°
1
Hist. Avg.
60°
37°
2
Hist. Avg.
60°
37°
3
Hist. Avg.
59°
37°
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 61° to 76°, with overnight lows between 43° and 53°. The average high for September is 70° with an average low of 48°. 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.
