Chennai features a tropical wet and dry climate, classified as *Aw* under the Köppen climate classification. Because it lies on the equator and is coastal, the city experiences hot and humid weather for the majority of the year.
Temperatures peak in late May and early June, a period locally known as *Agni Nakshatram* (fire star), with average highs frequently exceeding 38°C (100°F). The coolest months are December and January, offering a much more pleasant climate with average highs around 29°C (84°F) and lows around 21°C (70°F).
Unlike most of India, which receives its rain from the Southwest Monsoon, Chennai gets the bulk of its annual rainfall from the Northeast Monsoon between mid-October and mid-December. The city is highly vulnerable to tropical cyclones emerging from the Bay of Bengal during this period. The best time to visit Chennai is between November and February, when the heat and humidity are at their lowest.