Croatia: where to swim in September?
Croatia, in September: the sea is at 24.1 °C on average along the coast, from 23.4 °C to 24.6 °C depending on the spot. Where the water is warmest (24.6 °C), it is warm. Ideal for long swims and for being in the water all day.
Sea temperature, month by month
| Month | Average temperature | Depending on the spot | Where it is warmest |
|---|---|---|---|
| January | 14.3 °C | 13.0 °C – 14.9 °C | cold |
| February | 13.5 °C | 12.0 °C – 14.6 °C | cold |
| March | 13.2 °C | 11.6 °C – 14.4 °C | cold |
| April | 14.7 °C | 13.6 °C – 15.5 °C | cool |
| May | 17.4 °C | 16.8 °C – 18.1 °C | cool |
| June | 22.4 °C | 21.8 °C – 22.9 °C | pleasant |
| July | 25.3 °C | 24.9 °C – 25.7 °C | warm |
| August | 25.9 °C | 25.2 °C – 26.6 °C | warm |
| September | 24.1 °C | 23.4 °C – 24.6 °C | warm |
| October | 20.9 °C | 20.3 °C – 21.5 °C | pleasant |
| November | 18.7 °C | 17.8 °C – 19.7 °C | pleasant |
| December | 16.2 °C | 15.1 °C – 17.0 °C | cool |
Compared with August, the water cools down by 1.8 °C in September. The warmest month: August (25.9 °C). The coldest: March (13.2 °C).
Nearby, in September
- Poland 17.0 °C · cool
- Germany 17.0 °C · cool
- France 20.1 °C · warm
- Netherlands 17.7 °C · cool
- Lithuania 17.1 °C · cool
- Denmark 16.3 °C · cool
And right now?
For the temperature measured right now, station by station and to the hour: Croatia: water temperature
Frequently asked questions
What is the sea temperature in September?
Croatia, in September: 24.1 °C on average along the coast, from 23.4 °C in the coolest waters to 24.6 °C in the warmest (average of the years 2011 to 2025).
Can you swim in September?
Where the water is warmest (24.6 °C), it is warm. Ideal for long swims and for being in the water all day.
What is the best month for swimming?
The water is warmest in August (25.9 °C on average) and coldest in March (13.2 °C). Where the water is warmest, it goes above 20 °C in these months: June, July, August, September, October.
Where is the water warmest in September?
The warmest in September: Poland (17.0 °C), Germany (17.0 °C), France (20.1 °C). The coolest: Denmark (16.3 °C).
Where do these temperatures come from?
These are averages of the sea surface temperature from 2011 to 2025, computed from NOAA satellite images (OISST, one value about every 50 km), in a 100 km strip along the coasts of the main country: distant territories (overseas, remote islands) are not counted. It is an estimate, not a measurement taken at the beach: lakes and rivers are not included.