Weather in Chennai

Rain is the monsoon runs from July to December, inside an annual total of 1253 mm. The wettest month is November at 292 mm; the driest is February at 6 mm.

Chennai is in India at 13.1°N. The 2001–2020 NASA POWER daily record describes a monsoon climate with a sharp wet-dry split. May is the warmest month (average 32.1°C, high 36.5°C) and January is the coolest (average 24.6°C, low 21.0°C). On this site the months that score closest to a 22°C day, lighter rain, and moderate humidity are January, February, and March.

When Chennai gets wet

The monsoon in Chennai starts in July and ends in December (July, August, September, October, November, and December). November is the core of it at 292 mm. February is the other extreme, with 6 mm.

A rainy day here is a day with at least 1 mm in the NASA POWER series. November averages 17 such days; February averages 1.

Hot and cool months in Chennai

The heat peaks in May, when the typical afternoon is 36.5°C. The opposite pole is January, when mornings average 21.0°C.

Mean high across all twelve months is 32.3°C and mean low is 24.6°C. These are 20-year grid averages, so a city station can read a few degrees warmer or cooler.

Distinctive months in Chennai

January is the coolest month, with lows around 21.0°C and highs near 28.3°C. Rainfall is 17 mm. February is the driest month, averaging only 6 mm across 1 rainy days. Highs sit near 31.0°C. May is the warmest month. Afternoon highs average 36.5°C and nights settle near 27.8°C, with 55 mm of rain.

In October, Chennai averages 30.5°C by day and 25.0°C at night, with 264 mm of rain. November is the wettest month — 292 mm and 17 rainy days, with 82% humidity. December closes the monsoon: 126 mm over 9 rainy days, then the calendar dries.

Best months to visit Chennai

The three months with the highest comfort score are January, February, and March: January (24.6°C average, 17 mm, 77% humidity); February (26.3°C average, 6 mm, 71% humidity); March (29.2°C average, 15 mm, 66% humidity). They fall in calendar order. The score rewards averages near 22°C, lower rainfall, and humidity near 60%. It is a climate score, not a festival or price calendar.

If you want the monsoon itself — fewer crowds, greener landscape, heavier rain — aim at July–December instead of the score.

How Chennai compares inside India

Bengaluru is about 291 km away: Chennai is 3.5°C warmer than Bengaluru in its hottest month and 410 mm wetter over the year than Bengaluru. Bengaluru’s wettest month is September (151 mm) versus November here.

Coimbatore is about 428 km away: Chennai is 2.9°C warmer than Coimbatore in its hottest month and 110 mm wetter over the year than Coimbatore. Coimbatore’s wettest month is October (192 mm) versus November here.

Hyderabad is about 516 km away: Chennai is 1.4°C cooler than Hyderabad in its hottest month and 445 mm wetter over the year than Hyderabad. Hyderabad’s wettest month is August (190 mm) versus November here.