S
M
T
W
T
F
S
30
81°
72°
31
78°
69°
1
79°
67°
2
76°
66°
3
77°
63°
4
76°
65°
5
83°
65°
6
95°
73°
7
95°
74°
8
93°
74°
9
94°
76°
10
86°
75°
11
81°
73°
12
79°
71°
13
78°
71°
14
75°
70°
15
76°
70°
16
78°
70°
17
76°
68°
18
78°
69°
19
78°
69°
20
77°
69°
21
77°
70°
22
79°
69°
23
78°
67°
24
77°
67°
25
80°
66°
26
83°
68°
27
80°
67°
28
82°
64°
29
81°
65°
30
80°
66°
1
79°
65°
2
80°
67°
3
81°
65°
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 77° to 83°, with overnight lows between 64° and 68°. The average high for September is 80° 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.
