16.09
wed
wed
Day
72°F
SW 6 mph
Precip.
49%
49%
Night
59°F
W 4 mph
Precip.
45%
45%
17.09
thu
thu
Day
68°F
SW 5 mph
Precip.
67%
67%
Night
59°F
W 4 mph
Precip.
44%
44%
18.09
fri
fri
Day
72°F
SW 4 mph
Precip.
41%
41%
Night
61°F
SW 3 mph
Precip.
43%
43%
19.09
sat
sat
Day
72°F
S 4 mph
Precip.
38%
38%
Night
63°F
SW 2 mph
Precip.
42%
42%
20.09
sun
sun
Day
73°F
S 3 mph
Precip.
62%
62%
Night
63°F
N 2 mph
Precip.
66%
66%
21.09
mon
mon
Day
70°F
E 3 mph
Precip.
70%
70%
Night
61°F
W 2 mph
Precip.
50%
50%
22.09
tue
tue
Day
64°F
NE 2 mph
Precip.
71%
71%
Night
61°F
NE 2 mph
Precip.
48%
48%
23.09
wed
wed
Day
64°F
E 1 mph
Precip.
43%
43%
Night
63°F
NE 2 mph
Precip.
92%
92%
24.09
thu
thu
Day
66°F
S 1 mph
Precip.
71%
71%
Night
61°F
N 2 mph
Precip.
92%
92%
25.09
fri
fri
Day
63°F
NE 5 mph
Precip.
78%
78%
Night
61°F
NE 4 mph
Precip.
49%
49%
26.09
sat
sat
Day
68°F
NE 3 mph
Precip.
24%
24%
Night
59°F
N 2 mph
Precip.
31%
31%
27.09
sun
sun
Day
75°F
SE 4 mph
Precip.
12%
12%
Night
63°F
NW 1 mph
Precip.
43%
43%
28.09
mon
mon
Day
70°F
S 4 mph
Precip.
75%
75%
Night
61°F
W 2 mph
Precip.
45%
45%
29.09
tue
tue
Day
64°F
SE 1 mph
Precip.
75%
75%
Night
61°F
E 2 mph
Precip.
93%
93%
sea water
temperature
temperature
| San Jose |
monthly
weather
weather
| San Jose |
current
weather
weather
| San Jose |
7 days
forecast
forecast
| San Jose |
Sea water temperature in September, °F
Show year:
2026
2025
2024
The average sea water temperature in September of 2026 was 86.5°F. The highest and lowest sea temperatures during the month were 87.4°F and 85.6°F.
Air temperature in San Jose, °F
Precipitation total in San Jose, in.
* Charts above show average data for the last 3 years.
Best time for vacation in San Jose
San Jose on a weather map
Places in Costa Rica:
Name
°F
24 Hours Forecast
San Jose
Local time: 07:23
September 16, wednesday
0900
68°F
SW
5 mph
5 mph
1200
72°F
SW
6 mph
6 mph
1500
64°F
SW
5 mph
5 mph
1800
63°F
SW
4 mph
4 mph
2100
61°F
W
6 mph
6 mph
September 17, thursday
0000
59°F
W
4 mph
4 mph
0300
59°F
W
5 mph
5 mph
0600
59°F
SW
4 mph
4 mph
