S
M
T
W
T
F
S
30
93°
76°
31
94°
75°
1
92°
74°
2
92°
74°
3
90°
73°
4
87°
74°
5
87°
73°
6
90°
74°
7
91°
72°
8
92°
70°
9
91°
71°
10
90°
70°
11
91°
72°
12
90°
71°
13
91°
71°
14
87°
70°
15
91°
71°
16
91°
65°
17
84°
65°
18
83°
66°
19
83°
64°
20
86°
68°
21
88°
70°
22
89°
69°
23
85°
68°
24
83°
67°
25
88°
68°
26
87°
68°
27
86°
67°
28
83°
67°
29
88°
64°
30
85°
64°
1
81°
66°
2
84°
65°
3
78°
66°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Martinez
Martinez's September 2026 forecast shows daily high temperatures ranging from 78° to 94°, with overnight lows between 64° and 76°. The average high for September is 88° with an average low of 69°. 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 Martinez. See also: October | November | December.