Bulgaria is situated in the Southern part of the moderate climatic region of Europe. The territory of the country is subjected to the influence of the Atlantic ocean from the West and from the Northwest and Northeast - to the continental part of Central and Eastern Europe. The climate of Bulgaria is generally defined as moderate continental with well expressed transition to the South of Stara Planina. In the Southernmost regions of the country the influence of the Mediterranean is felt. In the mountainous regions at an altitude above 1000 m there is differentiated a mountainous climatic region with relatively low temperatures, heavy rainfall and continuous snow retention.
Winds vary in direction and velocity, relatively constant being the Northwest and West.
These cause warming up in spring and in summer bring rainfall, often accompanied by thunder. Comparatively frequent is the Northeastern wind bringing dry continental air masses - cold in winter and hot in summer. The average annual rainfall range is between 450 - 1300 mm, the better quantity falling over Western Bulgaria and the high mountains. The heaviest rains fall in May and June, in the high mountains - in winter. The complex relief structure and the small territory of Bulgaria do not create conditions for big rivers.