Bulgaria is characterized by two climatic regions: a continental climate in the north and a Mediterranean climate in the south. The country’s Mediterranean climate tends to be hot and dry in the summers and cool in winters. The mountains that differentiate the northern and southern regions have a significant impact on the country’s temperature. The continental north tends to have higher variation in temperature and precipitation compared to the coastal regions. Approximately 50% of the territory (5.2 million ha) is land used for agricultural purposes. An estimated 29.5% of the area is equipped for irrigation. Forests cover 34% of the total area of the country.
The mean monthly temperature in the country ranges from -1℃ to 22 °C. Coldest temperatures are experienced in the northern winter months of December and January and warmest temperatures during northern hemisphere summer months of July and August. Over the past century, the region has experienced gradual warming while the intensity and length of heat waves has increased in the Mediterranean region. Monthly mean precipitation ranges from 40-71 mm and varies seasonally; May and June have the highest levels of precipitation while two periods (February and March, and August and September) have the lowest levels of precipitation. Precipitation has varied over the past century, with recent short-term increases in precipitation that have resulted in flooding.
- Temperatures range from 15°C to 25°C, steadily increasing from March to June.
- Bulgaria has experienced a warming tendency over the past century, with a decreasing difference between maximum and minimum temperature.
- Average annual temperature consistently surpassed historical records of average temperature and has continued to hit record highs.
- Since the 1970s, a tendency towards warming was observed. 2014 recorded the highest temperature since 1901, with an average annual temperature of 12°C, which was 1.45 °C above average.
- Overall, winters for Bulgaria were milder in the second half of the 20th century with an increasing number of hot and dry spells.
- Dobrudzha in the northeast, the Black Sea coastal area, and parts of the Thracian Lowland usually receive less than 500 mm precipitation per year. The Thracian Lowland is often subject to summer droughts. High altitude areas, which receive the most precipitation amount in the country, can average over 1,000-1,100 mm per year.
- Changes in precipitation have been highly variable across the country.
- Increases in frequency of extreme rainfall and precipitation events, particularly the number of days with high precipitation (volume above 100 mm) have been observed.
- Snowy months have decreased, with a marked thinning in snow cover as well as changes in upper forest limit of deciduous forests and phonology.