The island of Sri Lanka lies atop the Indian tectonic plate, a minor plate within
the Indo-Australian Plate. It is positioned in the Indian Ocean, to the southwest of
the Bay of Bengal, between latitudes 5° and 10°N, and longitudes 79° and 82°E.
Sri Lanka is separated from the Indian subcontinent by the Gulf of Mannar and
the Palk Strait. According to the Hindu mythology, a land bridge existed between
the Indian mainland and Sri Lanka. It now amounts to only a chain of limestone shoals
remaining above sea level. It was reportedly passable on foot up to 1480 AD,
until cyclones deepened the channel.

The island consists mostly of flat-to-rolling coastal plains, with mountains rising only
in the south-central part. Amongst these is the highest point Pidurutalagala,
reaching 2,524 metres (8,281 ft) above sea level. The climate of Sri Lanka can be
described as tropical and warm. Its position endows the country with a warm climate
moderated by ocean winds and considerable moisture. The mean temperature ranges
from about 17 °C (62.6 °F) in the central highlands, where frost may occur
for several days in the winter, to a maximum of approximately 33 °C (91.4 °F) in other
low-altitude areas. The average yearly temperature ranges from 28 °C (82.4 °F) to
nearly 31 °C (87.8 °F). Day and night temperatures may vary by 14 °C (57.2 °F) to
18 °C (64.4 °F).

Rainfall pattern of the country 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 (98.4 in) of rain each month, but the leeward slopes
in the east and northeast receive little rain. Most of the east, southeast, and northern
parts of the country comprise the "dry zone", which receives between 1,200 mm (47 in)
and 1,900 mm (75 in) of rain annually. The arid northwest and southeast coasts receive
the least amount of rain at 800 mm (31 in) to 1,200 mm (47 in) per year. Periodic squalls
occur and sometimes tropical cyclones bring overcast skies and rains to the southwest,
northeast, and eastern parts of the island. Humidity is typically higher in the southwest
and mountainous areas and depends on the seasonal patterns of rainfall.

References from