Split’s sea runs about a month behind its air. In April the two are level, at 13.7°C air against a 13.8°C sea. By October the air has dropped to 16.8°C while the sea still holds 19.3°C. The swimming season ends later than the weather does.
The swimming calendar at Split
Split has city beaches you can walk to and island beaches you have to catch a boat to, and the same water temperature applies to both. That temperature is published by DHMZ for the Marjan station, which makes Split one of only three places on the entire Croatian coast where the sea has a monthly normal at all.
Sea temperature at Split (Marjan), January to December, °C. Source: DHMZ (meteo.hr), climate normals 1971–2000.
The shape of that strip is the point. February is the annual floor at 11.5°C, not January, because the sea keeps cooling after the air has bottomed out. The same inertia at the other end of the year is what buys you October: 19.3°C water under a 16.8°C sky, warmer than the sea manages in any month before June. On the day the coast was read live, 6 August 2026, Split was the joint-coldest station in the country at 26.0°C against a coast-wide mean of 27.5°C — one day’s reading, not a normal, and a useful corrective to the idea that central Dalmatia has the warmest water.
The beaches you have to catch a boat to
Split is the head of the largest ferry network in the country, and for beach purposes that network is the map. Ten state lines run out of the port under a public service obligation, which is what keeps them on the water outside the summer, and five of the ten carry a car.
| Line | Vessel | Carries cars | Where it calls |
|---|---|---|---|
| 602 | Car ferry | Yes | Vis town |
| 604 | Car ferry | Yes | Ubli (Lastovo) · Vela Luka (Korčula) · Hvar town |
| 631 | Car ferry | Yes | Supetar (Brač) |
| 635 | Car ferry | Yes | Stari Grad (Hvar) |
| 636 | Car ferry | Yes | Rogač |
| 9601 | Catamaran | No | Milna (Brač) · Rogač · Sutivan (Brač) |
| 9602 | Catamaran | No | Vis town · Hvar town · Milna (Brač) |
| 9603 | Catamaran | No | Jelsa (Hvar) · Stari Grad (Hvar) · Bol (Brač) |
| 9604 | Catamaran | No | Ubli (Lastovo) · Vela Luka (Korčula) · Hvar town |
| 9608 | Catamaran | No | Korčula · Prigradica (Korčula) · Hvar town |
The commercial operators add a second layer on top of that: Jadrolinija, Kapetan Luka (Krilo), Krilo Shipping Company and TP Line all run catamarans out of Split in summer, none of which carries a vehicle. Nationally, 17 of the 68 registered routes are commercial lines with no public service obligation, and they are the first thing to disappear when the season ends.
Departing from
Season
Switch that from Summer to Winter and the list halves. What survives is the state network: the car ferries to Supetar, Rogač, Stari Grad and Vis, and the state catamarans. That is the difference between a beach day you can plan in April and one you can only plan in August.
Two dates rather than one govern the cost of a beach day out of Split. The timetable thickens when the summer sailings are added; the tariff changes on 29 May and reverts on 27 September, on every line whose per-line tariff has been checked. On the Split–Vis car ferry, line 602, that is the difference between €7.20 and €9.10 for a foot passenger, and between €40.60 and €52.00 for a car under five metres. The car costs between five and six times the foot fare, and on an island beach day it is usually the useless half of the decision.
The famous beach near Split is not near Split
The beach everyone means is on Brač, at Bol, and Bol is reached by boat. State catamaran 9603 calls there on its way between Split and Jelsa; the Krilo Shipping service from Split to Bol and Jelsa is a commercial line with no public service obligation. The car ferry alternative does not go to Bol at all — line 631 lands at Supetar, on the other side of the island, and the rest is a drive.
The cost is a day, not a fare. The last sailing back fixes the length of your visit, and the per-line timetables for 631 and 9603 are not in the verified bundle, so no departure time appears on this page — check the operator’s own timetable for the day you are going rather than a third-party listing. If the return boat is the problem, the honest answer is to sleep on Brač rather than day-trip it.
Applied to a week in Split, that gives a simple division of labour. Walk to the city beaches on arrival and departure days, when a fixed return sailing would ruin the schedule, and use the state lines for the island days in between. The commercial catamarans are worth having in July and August, and worth ignoring when you are planning in May.
What do you need to work out next?
The water and the boats are settled. These come next.
Where to stay
Which part of Split puts me near water?
The ferry port and the swimmable side of the peninsula are not the same place.
Getting around
What else is a day trip from the port?
Ten state lines leave Split, and they run in February as well as August.
When to go
When does Split stop being swimmable?
The sea holds 19.3°C in October and 16.4°C in November.
Planning
Which Split beach is the shallow one?
Split's sea peaks at 23.6 °C in August and holds 19.3 °C into October.
Climate data: DHMZ (meteo.hr), climate normals 1971–2000. Ferry data: Agencija za obalni linijski pomorski promet (ZOLPP), 2026 state coastal line register and per-line timetables. No bathing-water grade for any named beach appears on this page. The IZOR record set has not been pulled.