Climate of Sri Lanka
The climate is tropical and warm, due to the moderating effects of ocean winds. Mean temperatures range from 17 °C in the central highlands, where frost may occur for several days in the winter, to a maximum of 33 °C in other low-altitude areas. Average yearly temperatures range from 28 °C to nearly 31 °C. Day and night temperatures may vary by 14 °C to 18 °C.
Rainfall pattern is influenced by monsoon winds from the Indian Ocean and Bay of Bengal. The “wet zone” and some of the windward slopes of the central highlands receive up to 2,500 millimetres of rain each year, but the leeward slopes in the east and northeast receive little rain. Most of the east, southeast, and northern parts of Sri Lanka comprise the “dry zone”.
The arid northwest and southeast coasts receive the least amount of rain per year. Humidity is typically higher in the southwest and mountainous areas and depends on the seasonal patterns of rainfall.