It is on the Coromandel coast of the Bay of Bengal and has the second longest beachfront of any municipality in the world.
Climate of Chennai is Tropical.
Chennai is situated in the Thermal Equator zone which prevents extreme changes in temperature. Chennai has mainly two seasons – summer (35-42°C / 95-108°F) Apr-Jun (Highest temperature ever recorded is 45°C / 113°F on 30 May 2003) and monsoon (Oct-Dec). It receives scanty rainfall from the south-west monsoon (Jun-Sep) while rest of India is lashed by heavy rains, but gets its bountiful rains from the north-east monsoon from October through December, thus amounting to about 125-150 cm (49-59 in) of rainfall annually. Rainfalls occur usually from October to December and dried up scrub lands bloom with greenery during this period.
December to February are the mildest months temperature – (19-28°C / 66-82°F). December to March is probably the best time to visit Chennai: the temperatures rarely exceed 30°C during midday and evenings are pleasant.
Climate is humid pretty much throughout the year because the city is on the coast. Summers are very hot and humid. Be sure take along light (not flimsy) clothing. Winter fashion has never been of any use in Chennai, wearing a sweater will leave you drenched in sweat in less than five minutes.
Tamil is the official language in Chennai, and also the first language of most locals. Almost all people speak Tamil, a classical language. Picking up some knowledge of the local language is useful to get by in Chennai as in every city in the world. However, knowledge of English is sufficient for the average visitor to the city. English education is widespread in Chennai . All educated people in Chennai can speak English while few understand simple English and can speak a few words. All important signboards are in English. All transactions with commercial establishments are in English. The English accent is different, there is a tendency to end sentences and words with -uh (Eg: I’m going there-uh.) and interrogative sentences with -ah (Eg: You are going there-ah?).
Unlike other major cities in Northern India, Hindi is not widely understood. While there has been a significant increase in Hindi speakers in recent years, most locals will find it difficult to understand when you try to speak to them in Hindi. You are better off speaking English than Hindi in most southern cities except Bangalore and Hyderabad.
Those native to Chennai and its suburbs speak the language of Tamil with a characteristic accent. Due to the proximity of the city to the State of Andhra Pradesh (where the official language is Telugu) and the presence of a sizable quasi Telugu speaking population in the city, there is heavy borrowing of Telugu words into the vocabulary of ‘Chennai Tamil’.’Chennai Tamil’ is popularly known as Madras Bashai. Another characteristic of Chennai Tamil is that the words are spoken fast, possibly in line with the fast-paced life in Chennai when compared with the rest of the state. Nevertheless, all educated people are taught standard Tamil in school, and standard Tamil is still used in more formal settings as well as in the news.