The Croatian coast has a Mediterranean climate, bringing it on average 2.600 hours of sunshine per year. During the summer, the average seawater temperature can be 24 – 27 degrees Celsius. There is a large number of sunny days with high temperatures. Usually, maestral winds, low humidity and cool nights keep it bearable.
Sailing early or late in the season (May or September), you should take into account that darkness comes quickly and early. All year round, twilight is virtually non-existent. During those times, the temperature drops rapidly. Along the coast, spring and autumn are mild, and winter is short.
Average monthly temperatures are: January 7°C, February 8°C, March 12°C, April 17°C, May 21°C, June 25°C, July 28°C, August 27°C, September 24°C, October 18°C, November 13°C, December 9°C. Longer-term climate information for several coastal cities can be found at EuroWeather.
In general, the weather conditions in the Adriatic Sea area can be rather unpredictable. Winds can literally change to opposite directions in minutes. It is very important to monitor the weather forecasts. Click here for the current nautical weather forecast from the meteorological service in Split.
The weather above the Adriatic Sea is determined by cyclones and anti-cyclones above the south and centre of the European mainland. The normal pattern is a cyclone moving from west to east above the Adriatic. At its front, it is bringing southern winds (so-called ‘Jugo’). This wind brings more warm and moist air, generally leading to cloudy and rainy weather.
Behind the cyclone, with a strengthened anti-cyclone that moves across the European mainland to the east, you’ll find a north-easterly wind with cool and dry air. Usually a storm follows, which will clear the sky, and after a temporary drop of temperature, the weather stabilises. The weather will be clear and quiet until the arrival of a new cyclone. During the summer, this brings a regular moderate maestral wind. The speed and direction of the cyclones determines the weather variation.
During the summer, cyclones are rarer. They usually pass further north across the European mainland. This leads to only small differences in weather conditions along the Croatian coast.
For me, the winds on the Adriatic Sea are amongst the most beautiful phenomena on this planet. So light, so fierce, so constantly changing. I have experienced myself more than once that we were nicely sailing along for hours and hours in a 15 knot wind. However, from one moment upon another the wind died down completely. After a few minutes, the wind came back, but now from a totally different direction.
All winds have a name there, and (apart from the direction they come from) some other specific characteristics. Below you find an overview of these winds and their most important features.
Between September and May, Jugo and Maestral are most common. During summer, Maestral is the prevailing wind.
BURA – NE
Cold and dry wind, blowing from the Croatian mainland towards open water. For sailors, this wind is very unreliable: she comes suddenly and with heavy gusts. Usually she precedes clear weather, but during the Bura conditions get foggy because of foam and water drops carried by the strong winds.
Bura is strongest at the Velebit Kanal (near Krk) and in the Gulf of Trieste. Because of the specific shape of the coast and the mountains, the winds get carried through ‘corridors’ of gaps and crevices and between high mountain ranges, towards the coast. The picture below shows the major ‘corridors’, where Bura is most dangerous and treacherous. Respect Bura or feel sorry later!
1) Gulf of Trieste, (2) Kvarner, (3) Velebit Kanal, (4) Sibenik, (5) Split – Makarska, (6) Peljesac and (7) Dubrovnik.
During the summer, you will usually find local Bura, lasting no longer than several days. During winter, however, Bura can blow for weeks at a time, bringing cold weather from the continent to the coast.
The picture below shows the so-called ‘Black Bura’. Less gusty, but usually bringing rain or snow.
JUGO – SE
‘Jug’ is the Croatian word for South. The Jugo is a warm, most, south-easterly wind. It is not a ‘sudden’ wind like Bura, but it develops gradually over a 24 – 36 hour period. The wind occurs all over the Adriatic Sea. It brings high waves because of the water being pushed into the Adriatic towards the northern shelves. Usually, it is a very constant wind. During the summer it is mainly a local wind, more common along the southern section of the Adriatic coast. From March to June the Jugo also regularly occurs along the northern sections of the coast. Jugo often brings clouds and rain along.
MAESTRAL – NW
A local wind coming from the sea towards the mainland. Very common from Spring to Autumn, and strongest during July and August. This wind often starts during the morning (from 10:00 AM onwards) when temperature differences between the land mass and water become bigger. It gradually builds up until approximately 15:00 hours, and then decreases gradually, dying out completely around sunset. Maestral is a thermic wind, caused by the temperature differences of land mass and the sea.
This is the wind that my windsurfing friends are always waiting for (usually in vain…).Maestral brings beautiful weather and white clouds. Furthermore, it takes away the worst of the heat during very warm days. Usually stronger in the south Adriatic area, and not so strong in the north.
A very special phenomenon is the ‘midnight maestral’. After very warm days it can start blowing in the middle of the night, usually lasting until ± 03:00 AM.
BURIN – NE
Burin occurs during the summer, blowing from the mainland.
TRAMONTANA – N
Comparable to Bura. One of my favourites, because it usually is relatively mild (15 – 25 knots) and very constant. Great for sailing.
LEVANAT – E
Comparable to Bura.
PULENAT – W
In all my years of sailing the Adriatic, I cannot remember ever experiencing this wind during my usual sailing periods (May – July).
LEBIC – SW and OSTRO – S
These are ‘Jugo’-variations. However, they blow when there is a cyclone above the Adriatic Sea. Usually brings clouds and rain, and is accompanied by a strong drop of the air pressure. These southern winds take days to develop, lasting 5 – 6 days (longer during winter).