Adriatic sea

Sea temperatures
The Adriatic Sea belongs to the group of warmer seas with a noticeable annual change in the surface temperature of the sea. The average annual temperature is 11°C, maximum temperatures are in July and August, and minimum temperatures in February. The lowest winter surface temperature of the sea is around 7°C but on rare occasions can be even lower. Temperatures rise in spring and reach around 18°C, and in summer rise to 22°C-25°C and in the southern Adriatic to 27°C. The lowest sea temperatures are in river mouths or by underground sources of fresh water.

Depth of the sea and the sea bed
The Adriatic Sea is shallowest in Istria where its depth does not exceed 50m. From Pula the seabed drops down to the Jabuka Pit where the greatest depth is around 240m. From the Jabuka Pit the seabed again rises up to the Palagruža Sill where the greatest depth is around 130m. South of the Palagruža Sill the seabed drops steeply towards the South Adriatic Pit where the greatest measured depth is around 1300m.
The Adriatic seabed is rough as a consequence of tectonic movements which occurred several million years ago. In certain places the seabed has been smoothed by sediment but river mouths make the seabed muddier.

Sea tides
The sea tides of the Adriatic Sea are of the mixed type, which means that they have a half daily rhythm during full and new moons, and a daily rhythm in the first and last quarters. High and low tides have relatively low amplitudes, which increase from the south towards the north. Thus in the southern Adriatic the difference is around 40cm while in Istria it is about 1m. In narrow channels and inlets the tide can rise significantly during a strong Bura.

Sea currents
The sea currents in the Adriatic Sea do not change dramatically and do not have a significant influence on the safety of shipping. They are mostly felt when manoeuvring a boat in harbours or near river mouths. The average speed of sea currents is around 0.5 knots but they can reach a speed of 4 knots near river mouths and in narrow channels.

Salinity of the sea
The salinity of the Adriatic Sea is on average 38.30%, i.e. 38.30g of salt can be obtained from 1kg of water. Near the coast and near river mouths the salinity is somewhat lower that this figure, and it is lower in the northern compared to the central and southern Adriatic.