S
M
T
W
T
F
S
30
74°
51°
31
76°
57°
1
79°
59°
2
84°
58°
3
86°
58°
4
80°
50°
5
73°
51°
6
75°
55°
7
75°
50°
8
74°
50°
9
73°
54°
10
71°
55°
11
72°
54°
12
72°
51°
13
71°
54°
14
73°
56°
15
79°
56°
16
80°
48°
17
76°
48°
18
74°
47°
19
79°
49°
20
78°
56°
21
77°
51°
22
70°
48°
23
69°
49°
24
69°
46°
25
68°
46°
26
70°
45°
27
68°
54°
28
67°
53°
29
66°
49°
30
68°
51°
1
73°
53°
2
72°
52°
3
64°
48°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in St. Johns
St. Johns's September 2026 forecast shows daily high temperatures ranging from 64° to 86°, with overnight lows between 45° and 59°. The average high for September is 74° with an average low of 52°. 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 St. Johns. See also: October | November | December.
