S
M
T
W
T
F
S
30
77°
64°
31
80°
65°
1
82°
60°
2
77°
59°
3
76°
58°
4
76°
57°
5
77°
57°
6
77°
61°
7
79°
57°
8
78°
62°
9
81°
62°
10
80°
61°
11
79°
60°
12
80°
62°
13
80°
62°
14
79°
61°
15
80°
62°
16
80°
60°
17
77°
61°
18
78°
61°
19
77°
60°
20
78°
60°
21
77°
58°
22
77°
51°
23
70°
52°
24
Hist. Avg.
77°
56°
25
Hist. Avg.
77°
56°
26
Hist. Avg.
77°
55°
27
Hist. Avg.
76°
55°
28
Hist. Avg.
76°
54°
29
Hist. Avg.
76°
54°
30
Hist. Avg.
75°
54°
1
Hist. Avg.
75°
53°
2
Hist. Avg.
74°
53°
3
Hist. Avg.
74°
52°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Monrovia
Monrovia's September 2026 forecast shows daily high temperatures ranging from 70° to 82°, with overnight lows between 51° and 65°. The average high for September is 78° with an average low of 60°. 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.
