Natural heritage
METEOROLOGY

CLIMATE ON THE KORNATI ISLANDS

In accordance with previous researches, the Kornati islands are located, in meteorological terms, between two different areas: the northern Adriatic, which is during spring and fall more under the influence of Genoa cyclones and the southern Adriatic Sea which is during summer longer affected by subtropical belt of high atmospheric pressure. Because of the relatively small area and small altitude, the climate in the entire area of the Kornati islands is almost completely equal. Because of the sparse ground vegetation, the dew is usually abundant and partly replaces the rain. According to Koeppen’s division, Kornati have olive climate, Cs' (moderately warm rainy climate, with hot and dry summers, and the most rainfall in the autumn).

The air temperature varies from the average 8 ° C in February up  to an average 25 ° C in July and August, and annually about 16 ° C. The highest maximum air temperature recorded at the weather station V. Sestrica in Kornati was 36.4 ° C, the lowest minimum -3.8 ° C. Even 270 days a year are warmer than 10°C. Average number of cold days (temperatures lower than 0°C) during one year is 4.2. Warm days (the highest temperature at least 25°C) last 90 days per year (starting in May and lasting until October), while there are approximately 40 hot days (maximum temperature at least 30°C), and they last from May to September (most of them in August = 16.9).

Cloudiness is small: during the cloudiest winter months clouds cover on average only slightly more than half of the sky, and during summer a quarter. August has on average 2 cloudy and 22 clear days (during whole year there are twice as much clear days than the cloudy ones, 151:74). However, it is interesting that on almost every cloudy day it rains. The main rain maximum is in October (in other parts of Croatia it is November).

The most common wind on the Kornati islands is the north-eastern wind (19.4%), and the strongest is sirocco. During summer summer breeze prevails. In general, movement of air masses from sea to land dominates these areas. Force 1 to 3 winds prevail in 70% of cases (from light breeze to light winds). Strong winds (force 6 or more winds) blow about 37 days a year, including the fact that they do not last longer than 5 days during December when they are most common. Stormy wind lasts 5.8 days per year, usually in December. Silence appears in 15,4% of cases per year.

The sun shines between 2600 and 2700 hours per year in the Kornati archipelago. Winter daily insolation is approximately 4 hours, and in summer approximately 11 hours. Ultraviolet radiation in Kornati is only approximately 5% of the total radiation.

ery interesting surveies were conducted for the purpose of determination of meteorological features of the climate in the Kornati archipelago. Connected with this, the most prominent singularities have been defined as follows: drop in temperature on January 8th, drop in temperature on February 13th, increase in temperature on March 25th, drop in temperature on April 17th, increase in temperature on July 24th, increase in temperature on September 22nd, increase in temperature on November 13th, increase in temperature on December 18th. From five-days singularities the most prominent are: drop in temperature in the second five-day period of January, drop in temperature in the third five-day period in February,  drop in temperature in the third  five-day period in April,   drop in temperature in the fourth five-day period in June, drop in temperature in the second five-day period in  August, increase in temperature in third five-day period  in November, increase in temperature in the fourth five-day period in Decemer.  From ten-days singularities the most prominent are : drop in temperature in the second ten-days period in February, drop in temperature  in  the second ten-days period in April, and increase in temperature in the second ten-days period in  August.