Karnataka witnesses three types of climate. The state has a dynamic and erratic weather that changes from place to place within its territory. Due to its varying geographic and physio-graphic conditions, Karnataka experiences climatic variations that range from arid to semi-arid in the plateau region, sub-humid to humid tropical in the Western Ghats and humid tropical monsoon in the coastal plains.
More than 75 percent of the entire geographical area of Karnataka, including interior Karnataka, witnesses arid or semi-arid climate. Karnataka has about 15 percent of the total semi-arid or 3 percent of the total arid areas marked in India.
Meteorological regions of Karnataka
Due to the climatic difference Karnataka is divided into three meteorological regions:
- Coastal Karnataka: This region stretches over the districts of Udupi, Uttara Kannada and Dakshina Kannada. The entire coastal belt and the adjoining areas have tropical monsoon. The area receives heavy rainfall. The average annual rainfall in Coastal Karnataka is about 3456 mm, which is much more than the rainfall received in the other parts of the state.
- North Interior Karnataka: This region extends over the districts of Bagalkot, Belgaum, Bijapur, Bidar, Bellary, Dharwad, Haveri, Gadag, Gulbarga, Koppal and Raichur. This area is an arid zone. North Interior Karnataka receives the least amount of rainfall in the state and the average annual rainfall is just 731 mm.
- South Interior Karnataka: This region spreads over the districts of Bangalore Rural, Bangalore Urban, Chitradurga, Chamrajnagar, Chikmagalur, Hassan, Kodagu, Kolar, Mysore, Shimoga and Tumkur. This zone experiences semi-arid type of climate. South Interior Karnataka receives an annual average of 1286 mm rainfall.
Seasons in Karnataka
Karnataka experiences the following four seasons in a year:
- Summer: The summer season starts from March and extends till May. April and May are the hottest months in Karnataka. During these two months the weather turns very dry and uncomfortable in the state.
- Monsoon: The monsoon season begins in June and lasts until September. During the month of June humidity and temperature soars in the state. It is also the month when the South West monsoon winds bring rainfall to the southern part of the state. From July to September the heat reduces to an extent due to the rainfall but the humidity stays high. The district of Udupi receives the highest average rainfall while the districts of Chitradurga, Bijapur and Koppal receive the lowest average rainfall.
- Post-Monsoon: The post-monsoon season begins from October and continues until December. This period brings about a pleasant change in the weather. The state receives a few spells of rain associated with the north-eastern monsoon which affects the south-eastern parts of Karnataka. The humidity reduces considerably during this period of the year.
- Winter: The winter season extends from January to February. These are the coldest months in most parts of Karnataka and the temperature dips low. The weather remains pleasant as the humidity reduces considerably.
Temperature in Karnataka
Karnataka experiences lowest temperature during the month of January and then the temperature gradually increases. The temperature begins to soar rapidly during the month of March. The southern parts of the state generally experience the highest temperature during the month of April while in the coastal plains the temperature reaches its maximum during the month of May. Post monsoon, during the months of October and November the temperature decreases in the state and comes down further during the month of December.
The average high temperature during summer is 34 degrees Celsius across the state. The average day temperature is 29 degrees Celsius in the monsoon season. During winter temperatures range from 32 degrees Celsius to below 20 degrees Celsius.
Till date the highest temperature recorded in Karnataka was 45.6 °C (114 °F) at Raichur on 23rd May 1928. The lowest temperature recorded was 2.8 °C (37 °F) C at Bidar on 16th December 1918.