S
M
T
W
T
F
S
30
80°
69°
31
80°
69°
1
79°
68°
2
80°
68°
3
77°
67°
4
77°
68°
5
76°
67°
6
77°
66°
7
78°
67°
8
80°
69°
9
81°
69°
10
81°
68°
11
80°
69°
12
80°
68°
13
79°
67°
14
74°
67°
15
76°
65°
16
75°
66°
17
79°
67°
18
76°
65°
19
77°
66°
20
79°
65°
21
78°
64°
22
80°
66°
23
79°
65°
24
80°
64°
25
80°
64°
26
79°
59°
27
75°
57°
28
72°
58°
29
72°
62°
30
73°
67°
1
78°
68°
2
79°
62°
3
80°
57°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in National City
National City's September 2026 forecast shows daily high temperatures ranging from 72° to 81°, with overnight lows between 57° and 69°. The average high for September is 78° with an average low of 66°. 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 National City. See also: October | November | December.
