Due to the location of Sri Lanka, within the tropics between 5o 55' to 9o 51' North latitude and between 79o 42' to 81o 53' East longitude, the climate of the island could be characterized as tropical.
The central part of the southern half of the island is mountainous with heights more than 2.5 Km. The core regions of the central highlands contain many complex topographical features such as ridges, peaks, plateaus, basins, valleys and escarpments. The remainder of the island is practically flat except for several small hills that rise abruptly in the lowlands. These topographical features strongly affect the spatial patterns of winds, seasonal rainfall, temperature, relative humidity and other climatic elements, particularly during the monsoon season.
The Climate of Sri Lanka is dominated by the above mentioned topographical features of the country and the Southwest and Northeast monsoons regional scale wind regimes. The Climate experienced during 12 months period in Sri Lanka can be characterized in to 4 climate seasons as follows.
1. First Inter-Monsoon Season - March - April
2. Southwest Monsoon Season - May - September
3. Second Inter-Monsoon Season - October - November
Northeast Monsoon Season - December - February