The Krka River is a karst phenomenon. In an area with extremely scarce water, the 72.5 km long course of the river is truly a miracle of nature.
Marine influences extend deep into the valley of the Krka River, and significantly affect the climate conisitions throughout the entire National Park. The climate classification of the Krka National Park according to the Köppen designation is Csa, meaning moderately warm Mediterranean climate with dry and hot summers. The Krka River flows from Knin to Šibenik, so the climate characteristics are analyzed based on data from weather stations in these two cities. With an average of 2 647 hours a year of sunshine in Šibenik and 2 377 in Knin, the area of the Krka National Park is among the sunniest parts of Croatia.
All 109 square kilometers of the Krka National Park are located in the southern part of northern Dalmatia. The area is characterized by changes throughout four distinct seasons. The gloomy and stormy winter weather alternates with the beautiful and sunny summers. The mean annual air temperature in Knin is 13°C, two degrees less than in Šibenik, which measures 15°C due to maritime influence. The average air temperature in January, the coldest month of the year, is about 7°C in Šibenik, and in Knin about 5°C, while in the hottest month, July, it meaures 25°C in Šibenik and 23°C in Knin. Due to the influence of the sea, which cools down slowly, autumn is warmer than spring. There is little likelihood of very low temperatures occurring in the Krka National Park.
The proximity of the sea and the surrounding mountains affect the amount of precipitation. Most precipitation occurs during the autumn and winter. A third of the total annual rainfall falls from October to December, so at that time the river is most abundant. The least precipitation falls in the summer, particularly in July. Snowfall in this area is very rare, especially on the seacoast, and can be expected occasionally as a rare surprise in December or January.
Apart from the being the sunniest, the region of the Krka National Park is also among the most unclouded parts of Croatia. Autumn is less sunny than spring, and the least sun can be expected in December and January, when days are the shortest and most cloudy. Annually, more than 100 bright days and about 90 cloudy days a year are normal, but even in the gloomiest winter months no more than a dozen cloudy days can be expected. Fog also rarely appears, so only seven to ten foggy days a year are to be expected.
Along the valley of the Krka River, the winds of the cold half of the year prevail: the northeasterly – bura and the southeasterly – jugo. The bura makes itself felt in the entire area, while the jugo is only dominant in the lower course of the Krka River. In clear weather n the summer, a gentle afternoon wind from the west or southwest develops, the maestral.
The most favorable bio-meteorological conditions prevail from the middle of May until the middle of June, when the entire day is usually pleasant. And September is also mostly pleasant, with hot afternoons, ideal for an active tour of the National Park.
