Hello,
@Ursula! Welcome to the forum!
Chennai is located at the Coromandel Coast of the Bay of Bengal. It is also located very close to the equator. Hence, the region experiences hot and humid weather all-year round. But since it's nearby the coast, there's no extreme variations in its weather conditions. There are slight variations in the weather depending on the season, but count on the hotness to remain.
Now, during the months of March to June, these are the summer season months. The hottest months would be from late May to early June. Temperatures can go as hot as 45°C during these months. However, those places near the coastline experiences some respite from the heat especially at night. But generally, the heat and humidity during these months can be unbearable. It is not an advisable time to go to Chennai, especially for sightseeing.
From July to September, these are the monsoon months. The region receives moderate to heavy rainfall during this time. The residents do rejoice to at least have some escape from the heat. However, cyclones can hit the region due to its proximity to the Bay of Bengal. It's not advisable as well to visit during these months except if you particularly enjoy the rainy season.
The winter season, from October to February, are the best months for visiting Chennai. January is the coldest month of the year. Temperatures vary between 15°C to 22°C. From mid-October to mid-December, it's not unusual to experience some rainfalls. This is the best season for travelling to Chennai as the weather is pleasant for sightseeing and other activities. Don't forget to bring your umbrella in case the rain falls though.
I hope this helps.
