17.09
thu
thu
Day
88°F
NW 16 mph
Precip.
23%
23%
Night
81°F
NW 10 mph
Precip.
32%
32%
18.09
fri
fri
Day
88°F
W 14 mph
Precip.
15%
15%
Night
82°F
NW 11 mph
Precip.
11%
11%
19.09
sat
sat
Day
86°F
W 15 mph
Precip.
16%
16%
Night
81°F
NW 8 mph
Precip.
55%
55%
20.09
sun
sun
Day
86°F
W 16 mph
Precip.
6%
6%
Night
81°F
NW 9 mph
Precip.
10%
10%
21.09
mon
mon
Day
86°F
W 15 mph
Precip.
17%
17%
Night
81°F
NW 11 mph
Precip.
31%
31%
22.09
tue
tue
Day
86°F
W 15 mph
Precip.
4%
4%
Night
81°F
W 12 mph
Precip.
25%
25%
23.09
wed
wed
Day
86°F
W 14 mph
Precip.
36%
36%
Night
82°F
W 12 mph
Precip.
30%
30%
sea water
temperature
temperature
| San Juan |
monthly
weather
weather
| San Juan |
current
weather
weather
| San Juan |
14 days
forecast
forecast
| San Juan |
Sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 85.1°F. The highest and lowest sea temperatures during the month were 85.5°F and 84.2°F.
Sea water temperature in October, °F
Show year:
2025
2024
2023
The average sea water temperature in October of 2025 was 85.5°F. The highest and lowest sea temperatures during the month were 86.0°F and 84.7°F.
Air temperature in San Juan, °F
Precipitation total in San Juan, in.
* Charts above show average data for the last 3 years.
Best time for vacation in San Juan
San Juan on a weather map
Places in Puerto Rico:
Name
°F
24 Hours Forecast
San Juan
Local time: 00:59
September 17, thursday
0300
81°F
NW
15 mph
15 mph
0600
81°F
NW
12 mph
12 mph
0900
84°F
NW
14 mph
14 mph
1200
88°F
NW
16 mph
16 mph
1500
88°F
W
14 mph
14 mph
1800
82°F
W
14 mph
14 mph
2100
82°F
W
11 mph
11 mph
September 18, friday
0000
81°F
NW
10 mph
10 mph
