S
M
T
W
T
F
S
30
78°
56°
31
77°
55°
1
78°
56°
2
76°
54°
3
75°
53°
4
76°
55°
5
77°
59°
6
76°
59°
7
74°
56°
8
77°
53°
9
74°
53°
10
78°
60°
11
80°
58°
12
80°
60°
13
79°
56°
14
78°
55°
15
74°
50°
16
73°
50°
17
69°
58°
18
76°
56°
19
77°
55°
20
75°
48°
21
78°
47°
22
72°
45°
23
75°
54°
24
76°
52°
25
73°
46°
26
Hist. Avg.
68°
47°
27
Hist. Avg.
68°
47°
28
Hist. Avg.
68°
46°
29
Hist. Avg.
67°
46°
30
Hist. Avg.
67°
46°
1
Hist. Avg.
66°
45°
2
Hist. Avg.
66°
45°
3
Hist. Avg.
65°
44°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in St. Johns
St. Johns's September 2026 forecast shows daily high temperatures ranging from 69° to 80°, with overnight lows between 45° and 60°. The average high for September is 76° with an average low of 54°. 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.
