S
M
T
W
T
F
S
30
87°
61°
31
85°
59°
1
82°
59°
2
82°
60°
3
83°
61°
4
85°
65°
5
88°
65°
6
87°
64°
7
87°
62°
8
82°
58°
9
80°
57°
10
80°
56°
11
81°
56°
12
80°
57°
13
79°
55°
14
78°
56°
15
79°
57°
16
79°
57°
17
82°
58°
18
82°
56°
19
83°
56°
20
Hist. Avg.
83°
59°
21
Hist. Avg.
82°
58°
22
Hist. Avg.
82°
58°
23
Hist. Avg.
82°
58°
24
Hist. Avg.
81°
57°
25
Hist. Avg.
81°
57°
26
Hist. Avg.
81°
56°
27
Hist. Avg.
80°
56°
28
Hist. Avg.
80°
56°
29
Hist. Avg.
80°
55°
30
Hist. Avg.
79°
55°
1
Hist. Avg.
79°
54°
2
Hist. Avg.
78°
54°
3
Hist. Avg.
78°
54°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
*Temporarily Unavailable
September Weather in Guam
Guam's September 2026 forecast shows daily high temperatures ranging from 78° to 88°, with overnight lows between 55° and 65°. The average high for September is 82° with an average low of 59°. 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 Guam. See also: October | November | December.
