S
M
T
W
T
F
S
30
91°
71°
31
87°
67°
1
87°
62°
2
87°
61°
3
85°
62°
4
84°
64°
5
85°
70°
6
89°
73°
7
93°
72°
8
89°
68°
9
87°
67°
10
92°
70°
11
89°
70°
12
91°
67°
13
88°
68°
14
89°
64°
15
92°
69°
16
91°
68°
17
91°
67°
18
88°
64°
19
84°
63°
20
86°
64°
21
88°
64°
22
89°
65°
23
88°
65°
24
85°
62°
25
81°
59°
26
80°
59°
27
79°
58°
28
80°
58°
29
82°
60°
30
82°
62°
1
81°
59°
2
84°
61°
3
87°
65°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
September Weather in Monrovia
Monrovia's September 2026 forecast shows daily high temperatures ranging from 79° to 93°, with overnight lows between 58° and 73°. The average high for September is 86° with an average low of 65°. 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 Monrovia. See also: October | November | December.
