Split averages 25.7°C in July and 8.0°C in January, with a mean daily maximum of 30.0°C in July — the highest of the eight DHMZ stations. The sea peaks a month later, at 23.6°C in August, and is still 19.3°C in October.
Twelve months at Split Marjan
Split’s normals come from the Marjan station on the peninsula above the old town. Read the table by columns rather than rows: the mean air column is a smooth curve, the days above 30°C column is a spike three months wide, and the sea column is the same curve as the air shifted about six weeks to the right.
| Month | Mean air °C | Mean daily max °C | Mean daily min °C | Sea °C | Days ≥25°C | Days ≥30°C | Rain mm | Rain days | Sun h/day |
|---|---|---|---|---|---|---|---|---|---|
| January | 8.0 | 10.4 | 5.6 | 12.0 | 0.0 | 0.0 | 73.7 | 7.9 | 4.3 |
| February | 8.4 | 11.2 | 5.7 | 11.5 | 0.0 | 0.0 | 61.2 | 7.2 | 5.4 |
| March | 10.6 | 13.8 | 7.8 | 11.9 | 0.0 | 0.0 | 63.4 | 7.5 | 6.0 |
| April | 13.7 | 17.2 | 10.6 | 13.8 | 0.1 | 0.0 | 61.9 | 7.7 | 7.0 |
| May | 18.9 | 22.7 | 15.4 | 17.3 | 9.1 | 0.1 | 61.6 | 6.6 | 8.8 |
| June | 22.8 | 26.8 | 18.9 | 21.1 | 22.0 | 5.0 | 47.3 | 5.7 | 10.2 |
| July | 25.7 | 30.0 | 21.7 | 23.2 | 29.5 | 16.5 | 25.5 | 3.3 | 11.2 |
| August | 25.4 | 29.7 | 21.7 | 23.6 | 29.0 | 15.7 | 44.8 | 3.8 | 10.3 |
| September | 21.2 | 24.9 | 18.0 | 21.7 | 15.4 | 1.1 | 68.9 | 5.8 | 8.2 |
| October | 16.8 | 19.9 | 14.1 | 19.3 | 1.3 | 0.0 | 82.1 | 7.6 | 6.2 |
| November | 12.0 | 14.7 | 9.6 | 16.4 | 0.0 | 0.0 | 101.7 | 9.1 | 4.5 |
| December | 9.1 | 11.4 | 6.7 | 13.7 | 0.0 | 0.0 | 90.8 | 8.6 | 4.2 |
Two figures in there do most of the work. The 30.0°C July mean daily maximum is the highest of the eight stations, higher than Hvar’s 29.5°C and Dubrovnik’s 28.2°C, because Split is mainland with a mountain wall behind it rather than an island in open water. And the 25.5 mm of July rain across 3.3 rain days is the lowest monthly total anywhere in the set.
The other end of the year gets less attention and is where Split’s reputation is least reliable. November is the wettest month at 101.7 mm across 9.1 rain days, December the darkest at 4.2 hours of sun a day, January the coldest at 8.0°C with a 5.6°C mean daily minimum. None of that is severe, but it is wet: October to January carry 348.3 mm between them against 186.5 mm for June to September. Split’s winter is not cold, it is grey and it rains.
August · Split (Marjan)
The sea peaks at 23.6°C while the air falls back from 25.7°C to 25.4°C.
Push it to September and the sea barely moves while the warm days halve. Push it to October and the sea is still warmer than it was in May. Nothing about Split's year is symmetrical around midsummer.
Why the shoulder is lopsided
The sea at Split is 17.3°C in May and 19.3°C in October; 13.8°C in April and 16.4°C in November; 11.9°C in March and 13.7°C in December. Every autumn month is warmer in the water than its spring counterpart, by about two degrees in each case. On land the two halves are near enough identical, which is why so many people book the wrong one.
The practical version: a May trip and an October trip look the same on an air temperature chart and are two different holidays in the water. May buys you 9.1 days above 25°C and a sea nobody stays in; October buys you 1.3 warm days and a sea you can swim in daily. October and May take that apart properly.
The same lag explains a smaller thing that catches people out in the other direction. In January the sea at Split is 12.0°C and the air 8.0°C, so the water is warmer than the air above it. That holds from November through to April, and it is why the harbour front in February feels milder than the inland towns an hour away at the same latitude.
Mean days above 25°C at Split by month. Five months of the year record none at all. Source: DHMZ (meteo.hr), climate normals 1971–2000.
The strip shows the other half of the argument. Split's summer is not a long plateau: it is four months carrying almost every warm day in the year, with a collapse at each end.
The long record, kept separate
DHMZ also publishes a much longer Split Marjan series covering 1948 to 2024. It is a different dataset over a different period and is never mixed into the table above, but it is the better guide to the shape of the year because it averages seventy-seven of them.
| Month | Mean air °C | Days ≥25°C | Sunshine hours | Rain mm | Rain days |
|---|---|---|---|---|---|
| January | 8.0 | 0 | 131.5 | 77.8 | 11 |
| February | 8.5 | 0 | 146.0 | 65.2 | 10 |
| March | 10.8 | 0 | 188.6 | 63.2 | 10 |
| April | 14.4 | 0 | 219.7 | 62.0 | 10 |
| May | 19.2 | 9 | 271.4 | 57.5 | 9 |
| June | 23.4 | 23 | 309.0 | 49.0 | 8 |
| July | 26.2 | 30 | 353.3 | 26.6 | 5 |
| August | 25.9 | 29 | 328.0 | 41.3 | 5 |
| September | 21.6 | 17 | 247.1 | 70.9 | 8 |
| October | 17.2 | 1 | 198.9 | 77.0 | 9 |
| November | 12.7 | 0 | 130.5 | 115.5 | 12 |
| December | 9.4 | 0 | 120.8 | 103.7 | 12 |
On that record September carries 17 days above 25°C and October carries one. The 1971–2000 normals put September at 15.4 and October at 1.3. The two datasets disagree on the exact count and agree completely on the shape: the Croatian season does not taper, it stops, and it stops somewhere in the last week of September.
30.0°C
Split's mean daily maximum in July, the highest of the eight DHMZ stations.
The long record also gives July 353.3 hours of sunshine and November 115.5 mm of rain, the brightest and the wettest months of its year. Those are annual totals from the 1948–2024 series and belong only with each other.
Booking Split in July because it is central
Split is the most convenient base on the coast and the hottest station in the dataset. It averages 16.5 days above 30°C in July against Hvar's 14.0 and Dubrovnik's 7.7, and its mean daily maximum is 30.0°C for the whole month. The old town is stone, walled and largely unshaded.
If July is fixed and heat is a problem, the ferry out is cheaper than the air conditioning: the crossing to Hvar buys two and a half fewer days above 30°C and a drier month. If the dates are movable, September holds 15.4 warm days and a 21.7°C sea.
For what to do with the result, things to do in Split is organised around the same problem, and the beaches are where the sea column above stops being a statistic.
What do you need to work out next?
Split's year is settled. These are the decisions that follow it.
Where to stay
Which rooms suit a week of thirty-degree days?
Split records 30 days at or above 25 °C in July and 29 in August.
Getting around
Is an island base cooler?
Hvar records 14.0 days above 30°C in July against Split's 16.5.
When to go
Where did the guide actually put its stars?
Split city holds one of the 113 entries in the 2026 selection. Zagreb holds eighteen.
Planning
Where does the city itself swim?
Split counts 30 days at or above 25 °C in July and 29 in August.
Climate data: DHMZ (meteo.hr), climate normals 1971–2000. Climate data: DHMZ (meteo.hr), Split Marjan station, 1948–2024.