20.09
sun
sun
Day
84°F
N 4 mph
Precip.
45%
45%
Night
82°F
NE 4 mph
Precip.
50%
50%
21.09
mon
mon
Day
82°F
SW 1 mph
Precip.
30%
30%
Night
81°F
NW 10 mph
Precip.
63%
63%
22.09
tue
tue
Day
81°F
NW 16 mph
Precip.
80%
80%
Night
79°F
N 14 mph
Precip.
76%
76%
23.09
wed
wed
Day
82°F
N 15 mph
Precip.
37%
37%
Night
81°F
N 11 mph
Precip.
26%
26%
24.09
thu
thu
Day
81°F
N 7 mph
Precip.
71%
71%
Night
79°F
N 5 mph
Precip.
59%
59%
25.09
fri
fri
Day
84°F
N 5 mph
Precip.
54%
54%
Night
79°F
SE 5 mph
Precip.
44%
44%
26.09
sat
sat
Day
82°F
SW 7 mph
Precip.
20%
20%
Night
82°F
S 12 mph
Precip.
27%
27%
27.09
sun
sun
Day
84°F
SW 12 mph
Precip.
28%
28%
Night
82°F
S 11 mph
Precip.
22%
22%
28.09
mon
mon
Day
84°F
SW 12 mph
Precip.
14%
14%
Night
82°F
W 8 mph
Precip.
16%
16%
29.09
tue
tue
Day
86°F
NW 11 mph
Precip.
15%
15%
Night
81°F
N 5 mph
Precip.
31%
31%
30.09
wed
wed
Day
84°F
NW 1 mph
Precip.
58%
58%
Night
82°F
S 2 mph
Precip.
8%
8%
01.10
thu
thu
Day
84°F
NE 6 mph
Precip.
10%
10%
Night
82°F
SW 7 mph
Precip.
18%
18%
02.10
fri
fri
Day
84°F
W 5 mph
Precip.
27%
27%
Night
82°F
S 4 mph
Precip.
14%
14%
Sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 85.3°F. The highest and lowest sea temperatures during the month were 85.8°F and 84.9°F.
Sea water temperature in October, °F
Show year:
2025
2024
2023
The average sea water temperature in October of 2025 was 84.7°F. The highest and lowest sea temperatures during the month were 85.5°F and 84.0°F.
Air temperature in Guam, °F
Precipitation total in Guam, in.
* Charts above show average data for the last 3 years.
Best time for vacation in Guam
Guam on a weather map
Places in Northern Mariana Islands:
Name
°F
24 Hours Forecast
Guam
Local time: 00:20
September 20, sunday
0300
82°F
S
2 mph
2 mph
0600
82°F
NW
2 mph
2 mph
0900
84°F
N
4 mph
4 mph
1200
84°F
N
4 mph
4 mph
1500
84°F
NE
6 mph
6 mph
1800
82°F
NE
4 mph
4 mph
2100
82°F
NE
4 mph
4 mph
September 21, monday
0000
82°F
NE
4 mph
4 mph
