Tamil Nadu experiences a tropical climate, largely falling under the Köppen classifications of Tropical savanna (Aw) and Tropical dry-summer (As). Unlike most of India, which receives the bulk of its rainfall from the Southwest Monsoon (June to September), Tamil Nadu relies heavily on the Northeast Monsoon (October to December).
Summers (March to June) are typically hot and humid, especially in the coastal areas and inland plains, with average high temperatures frequently exceeding 38°C (100°F). Winters (December to February) are pleasant and relatively cool, making this the best time to visit. The state is highly vulnerable to cyclonic storms that form in the Bay of Bengal during the Northeast Monsoon, occasionally bringing heavy rains, flooding, and high winds to coastal districts.