Bulgaria has a predominantly continental climate with hot summers and cold winters, and with low annual precipitation which reaches its maximum in summer. Relief combines with location however, to permit air from the Mediterranean to penetrate some regions, and there are thus significant local variations.
The climate is most typically continental on the Danube platform, which is open to the north and east winds bringing cold in winter and heat in summer. At Pleven, January temperatures average 39°F and July temperatures 74.5°F. Rainfall in this region occurs mainly as summer thunderstorms, averaging 23 inches annually.
The Balkan Mountains restrict the southward passage of continental air, and the Thracian plain thus has a warmer transitional continental climate with more winter rain brought by the Mediterranean air which penetrates the Maritsa valley.
January temperatures at Plovdiv average 32°F, July temperatures 75°F; rainfall averages 21 inches yearly. Even stronger Mediterranean influences occur farther south. Kurdzali averages 35°F in January, and in the southward-facing Struma and Mesta valleys rain comes mainly in the winter.
A sheltered position on the Black Sea coast in the east gives Varna a milder, less extreme climate. Its many sunny days make the city a leading tourist center.
Climate in the mountains varies with altitude, being typically alpine near high summits like Musala Peak. The mountains also give the Sofia and other intermontane basins their specific climatic features: cold winters resulting from temperature inversions, and shelter from the wind throughout the year. It is this shelter that enables damask roses to be grown in Bulgaria's famous valley of roses, extending from Karlovo through Kazanlak, where the buds, picked at dawn in May, are distilled into attar of roses, used in making perfume. Bulgaria is the world's chief supplier of rose oil.
Vegetation ranges from the steppe-like grasslands of the Danube platform to the forests of the mountain slopes and the alpine plants, including edelweiss, of the high Balkan, Rila and Pirin ranges.
Oak and beech forests clothe the limestone slopes of the Stara Planina, walnut and chestnut are typical of the Maritsa valley, while the higher slopes of the Rhodope Mountains are thickly forested with conifers. In some parts of the country wild apple, pear and plum trees are numerous.
Wildlife in the forests and mountains includes bears, wolves, jackals, wild boars, eagles and falcons.
People and History
Bulgaria's population growth has been centered on the towns, and 59% of the people live there; 7% are Muslims and 27% are Orthodox Christians.
Bulgaria's earliest civilization, that of the Thracians, was established about 2500 BC. By AD 117, the area was under Roman rule. Slav settlers flooded in between AD 500 and 700, but were overrun by nomadic Asiatic Bulgars. The Bulgars became a ruling aristocracy, but absorbed Slav language and culture. Wars against the Byzantine Empire led to Byzantine occupation (1018-1186).
Later, the Bulgar Empire produced a thriving civilization; but this fell to the Ottoman Turks in 1396.
A Russo-Romanian invasion in 1877 forced the Turks to recognize Bulgarian independence. Fearing Russian success, the Western powers created the Principality of Bulgaria by the Treaty of Berlin in 1878, and Eastern Rumelia (south Bulgaria) was added in 1885.
The present frontiers are largely the result of the two Balkan Wars of 1912-13 in which Bulgaria claimed Macedonia. Bulgarian claims to Yugoslav Macedonia still cause ill feeling.
Bulgaria was strongly influenced by Germany in the 1930s, and entered the war on her side in 1941. Russian forces invaded in 1944, and the communists seized power. The tsarist monarchy was abolished in 1946, and a one-party people's republic established.
Bulgaria was a member of the Warsaw Pact group that existed from 1955 to 1991.