General
It’s a smart idea to know the general weather patterns in the Adriatic before booking a yacht charter in Croatia. When you want a bareboat charter, you become the skipper, the person in charge of the boat.
Aside from damage to the charter yacht, the skipper is also responsible for the cruise members’ welfare. As a result, knowing and keeping track of the weather forecast is an important aspect of the skipper’s job.
Even if you are not sailing in Croatia as a skipper, but rather as a passenger in your own cabin on a cruise ship or on a chartered crewed yacht with a captain, you must be familiar with the weather conditions in the Adriatic.
There are a variety of causes for this, ranging from stopping sea sickness to comprehending unexpected cruise path changes due to poor weather.
The location of cyclones and anti-cyclones over Central and Southern Europe determines weather conditions on the Adriatic.
A cyclone’s typical path is from west to east, carrying warm and moist winds in a southerly direction that trigger wet weather. On the Adriatic, the Jugo breeze beats most of the time.
As anticyclones shape to the east of Europe, the wind moves northeast, carrying cool, dry air.
The Bura wind blows most of the time on the Adriatic. Bura winds clear the skies and scatter rain clouds. Before the next cyclone, the atmosphere is calm and bright.
For a few days, the air temperature could be lower.
Nautical season
Basically, much of the year, the Adriatic is a perfect location for sailors. From early April to the end of October is the perfect time to cruise the Adriatic.
The tourism season is at its best during the summer months of June, July, and August. There are a lot of charter boats out at sea, as well as a lot of visitors and festivals.
During these months, it can be difficult to locate crew and available berths in some of the Adriatic’s most beautiful locations. April, May, September, and October are not as crowded as September and October, but they do have pleasant weather.
Winds could be a little heavier than at peak season. The daily temperatures are already high, and swimming is enticing. Several regattas take place at this period.
Sea, temperature and seasons
A brief introduction
Since the north Adriatic coast is very close to the Alps, there are some climatic variations between the north and south Adriatic coasts.
In the summer, they are less visible, but in the winter, the weather pictures of the north and south are often very different. The boundary between the two faces of the same sea is very plain – it’s cape Ploca, also known as Punta Planka among sailors, located two miles south of Rogoznica on the way to Sibenik on the way to Split.
Anticyclones and Cyclones
Changes in weather on the Adriatic determine changes in cyclones and anticyclones throughout central and southern Europe. Cyclones typically migrate from west to east through the Adriatic Sea.
On their front side, they bring southerly winds with warm and damp air, resulting in gloomy and rainy weather. The wind travels to the north-east, bringing cold and dry air, and the north-eastern wind chases the clouds, stabilizing the weather.
Behind the cyclone with the rising anticyclone and it spreading over the European land across the east, the wind moves to the north-east and carries cold and dry air, north-eastern wind chases the clouds, stabilizing the weather.
The atmosphere remains sunny and cool until the arrival of the next cyclone, with a regular landward breeze during the season.
This cycle of transition is typical of the Adriatic, with the only exception being how often and from where the cyclones arrive. They are less powerful and dipper in the summer and mainly fly north of the Adriatic; in the winter, they are more powerful and dipper.
They make their way from the Geneva Bay and the Triennia Sea through south Italy, the Adriatic Sea, and beyond to the southeast.
Summer and winter have distinct characteristics.
The variations between the north and south are much smaller in the summer, as both sides of the Adriatic are merged into one climate territory with many warm and sunny days, high normal temperatures that are moderated by a good landward wind, low humidity, and not too hot nights.
On the entire Adriatic, the sea surface temperature is between 24°C and 26°C. The variations between the north and south Adriatic become more apparent during the evenings as the summer progresses, although the daily temperatures remain relatively constant.
The sea temperature begins to fluctuate as the nights get colder. The sea begins to get cooler at the beginning of September. The sea temperature drops to 18°C and higher in the north, but it can still reach 22°C in the south. In the winter, the air temperature is also different.
The snow brought by a heavy storm is not so far away in the Trieste Bay and under the Velebit, while the weather on Hvar, Vis, and Korcula can be very good. Cape Ploca proves to be deserving of its name – the temperature boundary – particularly during the winter, when two types of weather often battle for dominance.
Temperatures
July and August are the hottest months, with air temperatures ranging from 25° C to 35° C (77° F to 95° F) and sea temperatures reaching 28° C (83° F).
Rain is a rare occurrence. This is where the majority of visitors arrive.
June and September are good months to visit the beach if you want to avoid the crowds. They’re still hot months, with normal temperatures around 25° C (77° F) and sea surface temperatures ranging between 20° C to 25° C (68° F – 77° F).
Sunbathing and swimming are also possible in April, May, and October, but it all depends on the temperature, and the southern Adriatic is likely to see more sunlight. Expect temperatures of 15° C to 25° C (59° F to 77° F) and sea temperatures of 16 to 21° C (61 – 70° F) throughout that period. This is a wetter and windier time of year.
In the winter, the air temperature ranges between 5 and 10 degrees Celsius (41 and 50 degrees Fahrenheit), while the sea temperature averages 12 degrees Celsius (54 degrees Fahrenheit).
Changes in the sea, currents, and waves
The fluctuations in high and low tide in the Adriatic are slight and have no impact on the sail’s defense.
The disparity between the tides is rarely greater than 40cm in the south, but when you travel north, the amplitudes increase – around Istra and Trieste Bay, the middle extreme amplitude is nearly 1m.
During long periods of heavy south winds, the tide in some small canals and bays can rise to the point that it floods over the walls of harbour beaches.
This is really far back (more so in the winter), and it’s typical of the south Adriatic’s wide and deep bays. The waves are normally stronger during south winds, and the water is colder than normal during hurricanes.
They are also affected by the atmosphere’s pressure.
Sea waves are minor and do not interfere with navigation. However, you must keep them in mind, particularly in some narrow canals where they can reach speeds of up to 4 knots.
Although the waves in the Adriatic are not as large as those in the seas, they can also be unpleasant for smaller vessels. While the south wind generates larger waves than the northeastern wind (the largest measured south wind wave was 10,8 meters, while the largest measured north-eastern wind wave was 7,2 meters), it would be incorrect to assume that the south wind waves are more destructive simply because they are larger.
In the other hand, northeastern wind waves are half as long as they are large, but they are also asymmetrical, causing the boat to struggle more in the waves. On the South, the landward wind waves can reach heights of up to 4 meters.
The Adriatic winds are a force to be reckoned with.
The weather on the Adriatic’s east side, especially the winds, has its own set of conditions. Fishermen have been able to decipher the small signals of nature and see what the sky will do next since the dawn of time.
That’s why you can’t go wrong by telling a fisherman about the forecast in the evening or the next day, and where the best spot to anchor for the night is.
The wind is blowing from the northeast.
The north-eastern (called ”bura” in Croatia) wind blows from the continent, from the eastern side of the Adriatic to the open sea, bringing bright air.
It blows in squalls into the shore and begins suddenly. In the Velebit Channel and the Gulf of Trieste, it is at its most strong. It blows as a local breeze in the summer which only lasts a few days. It will last anywhere from six to fourteen days in the winter.
It can be very inconvenient for smaller vessels.
The Adriatic, especially the northern portion, would be much more fun without it. It rarely blows for more than three days. It can start and stop within 24 hours if it’s local, but it can last a week if it’s big and continental, and it can get weaker or better many times during that time.
One of the most dangerous aspects of the wind is its sudden onset, particularly for inexperienced sailors. It can easily exceed 40 – 50 knots along the coast, and even more during the winter. It travels through the mountains to the sea, bringing cold and thick air with it. As a result, it’s best to hide in the bays under the mountains.
The wind from the south
The warm wind from the southeast (known in Croatia as “jugo” or “sirocco”) sweeps through the Adriatic, bringing clouds and rain with it during the cyclone.
The air pressure is dropping. It takes a long time to develop; you’ll normally find it two or three days before the case. It creates high, long waves as it blows through the canal. It normally lasts five to seven days, much longer than the north-eastern storm. It can occur as a local wind in the summer and is more common in the Adriatic’s southern reaches. It also blasts in the north between March and June.
And later in the snow. There are also what are known as “dry south winds,” which last longer, do not carry rain, but can be as strong as a hurricane.
Other winds
The north-western wind (called “Maestral” in Croatia) is a summertime local wind that blows from the sea. It normally begins between 10 and 11 a.m., peaks between 2 and 3 p.m., and then fades away at sunset. It ushers in pleasant conditions. It’s normally surrounded by a smattering of white clouds.
In the summer, the north-easterly breeze (known in Croatia as “Burin”) blows from the mainland.
A kind of bora is the northerly wind (known in Croatia as “Tramontana”).
The easterly wind ”Levante” is another kind of bora. ”Pulenat” blows from the west, and ”Lebic” from the south-west.
The breeze from the ground
This is a pleasant breeze that is beneficial to sailors and, in general, to everyone who loves the summer sea because it cools them down. It’s a thermal northeast breeze that blows every day. It’s common from spring to fall, with the best months being July and August.
It typically begins at 9 a.m. or 10 a.m. It reaches its peak in the afternoon and fades away with sunset.
It is normally weaker in the north Adriatic than in the south, where the force can be unpleasant for small boats in the canals between islands.
Unexpected storm (dubbed “Nevere”)
The sudden storm on the Adriatic, second only to the north-eastern, is probably the most unpleasant experience, particularly for small boats.
They’re thermal storms that come in fast from the west, from the open sea; they last just a few minutes but pack a punch. They’re most common in the summer, and as fall approaches, they become ever more strong.
Since time is of the essence, you should take every precaution at the first sign of a storm. If there is some way to get out of its way, you can do so. Before the hurricane begins, it is completely still, and even in the final minutes before it breaks, a wind blows directly into the storm, making it difficult to hear thunder.
As a result, many residents were caught completely unprepared by the storm.
Rain forecasts and information
Daily bulletins or radiotelephone forecasts provide information on the current condition and possible future of the atmosphere.
Forecasts on the radio. The general situation and prediction for the next 12 and 24 hours in the Adriatic and Otranto begin with a summary of the weather (i.e. wind 7 Bf freshening, sea 5 rising, fog, etc.). Three times a day, coastal radio stations RIJEKA RADIO, SPLIT RADIO, and DUBROVNIK RADIO broadcast forecasts in the national language, accompanied by English. MALTA RADIO, TRIESTE RADIO, and the Italian RAI service are also relevant radio stations.
When storms or other weather hazards are predicted, special warnings are broadcast, and they are repeated until the next period of radio silence.
For smaller parts (sectors/quadrants) named on a separate map, the current situation and forecast can be given (index map).
The Adriatic is divided into three sections by the Croatian naval meteorological service: northern, central, and southern.
Weather (meteorological) bulletins provide weather maps and tables for locations along the Croatian coast, as well as information on the synoptic situation and weather predictions. They are available from harbour masters’ offices or via NAVTEX (radio-telefax).
Weather information is available over the internet and radiotelephone from the Maritime Meteorological Centre in Split.
Weather reports
These channels broadcast weather forecasts at the following times (UTC):
0535, 1435, and 1935 Rijeka Radio VHF (channel 24)
Broken Radio VHF: 0545, 1245, and 1945 (channels 07, 21, 23, 28)
0625, 1320, and 2120 Dubrovnik Radio VHF (channels 04, 07)
Croatian Meteorological and Hydrological Service has an online weather forecast.
Croatian nautical forecast