S
M
T
W
T
F
S
30
66°
48°
31
64°
46°
1
62°
46°
2
61°
47°
3
61°
46°
4
62°
45°
5
62°
46°
6
61°
49°
7
62°
50°
8
65°
47°
9
64°
47°
10
61°
48°
11
62°
49°
12
63°
49°
13
65°
46°
14
63°
44°
15
59°
44°
16
58°
46°
17
61°
48°
18
63°
49°
19
64°
51°
20
64°
50°
21
63°
50°
22
64°
49°
23
62°
48°
24
63°
46°
25
60°
44°
26
58°
45°
27
57°
43°
28
60°
44°
29
59°
44°
30
60°
46°
1
59°
45°
2
59°
47°
3
Hist. Avg.
55°
41°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in St. John's
St. John's's September 2026 forecast shows daily high temperatures ranging from 57° to 66°, with overnight lows between 43° and 51°. The average high for September is 62° with an average low of 47°. 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. John's. See also: October | November | December.
