Its climate is continental with four distinct seasons in the North and Mediterranean and in the far South. Summers are long and hot, generally dry. Winters are cold and snowy in the North and quite mild with little snow in the South. In Bulgaria there is no best season, because every season has its own charm and beauty.

Maximum temperature in summer could reach 40 Celsius, while the winter temperature in the open northern plains and in mountains could drop down to minus 20 Celsius.
While the month with the highest precipitation is May, the driest period is August to September.

The rivers rise mainly in the highest mountains and flow into the Black Sea. and into the Aegean Sea . Bulgaria has 526 rivers longer than 2.3 km. The only navigable river is the Danube, which lies along the North Bulgarian border. There are good prerequisites for the development of adventure tourism: wild water rafting and canoeing, diving, hangliding and paragliding in the river valleys of Vatcha, Iskar, Chepelarska, Struma, and Mesta rivers.

The longest rivers on the territory of Bulgaria /in km/: Iskar /368.0 km/, Toundga /349.5 km/, Maritsa /321.6 km/, Osum /341.0 km/, Struma /290.0 km/, Yantra /285.5 km/, Kamchiya /244.5 km/, Arda /241.3 km/, Louda Kamchiya /200.9 km/ and Roussenski Lom /196.9 km/.

The longest rivers on the territory of Bulgaria /in km/: Iskar /368.0 km/, Toundga /349.5 km/, Maritsa /321.6 km/, Osum /341.0 km/, Struma /290.0 km/, Yantra /285.5 km/, Kamchiya /244.5 km/, Arda /241.3 km/, Louda Kamchiya /200.9 km/ and Roussenski Lom /196.9 km/.

There are about 330 natural lakes; the largest are the Black Sea lakes, Alepou, Arkoutino, Pomorie, Beloslav, Bourgas, Varna and the Shabla lakes, the most numerous /over 260/ are the high-mountain glacial lakes in the Rila and Pirin mountain ranges. Dams have been built as a part of waterpower systems: Iskar, Arda, Batak Water Power System, Belmeken-Sestrimo, Dospat-Vucha, and a great number of smaller dams.