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• Rainfall pattern is influenced by monsoon winds from the Indian Ocean and Bay of Bengal.

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• 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", which receives between 1,200 and 1,900 mm of rain annually.

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• The arid northwest and southeast coasts receive the least amount of rain at 800 to 1,200 mm per year.

 

• Periodic squalls occur and sometimes tropical cyclones bring overcast skies and rains to the southwest, northeast, and eastern parts of the island.

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• Humidity is typically higher in the southwest and mountainous areas and depends on the seasonal patterns of rainfall.

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