Weather in Chennai during monsoons

As Chennai lies on the coast and is closer to the thermal equator, moderate temperatures throughout the year are thoroughly enjoyed by all. Though, the weather in Chennai becomes hot and sweaty in the summers months of May and April as the mercury soars to more than 40°C.  While heavy rains in the monsoon season and the cyclone season (Bay of Bengal) lash the city, the Chennai weather in India becomes pleasantly cool during the winter months from December to Feb at 18 to 20°C, attracting many for a beachy vacation.

Rains in India are received from two monsoon seasons, i.e. the Southwest monsoons and the Northeast monsoons. But there is something peculiar about the weather in Chennai during the wet or not so wet monsoon months. This is, when the entire country receives rain from the southwest monsoon, the weather in Tamil Nadu (Chennai) remains the driest. It’s because Chennai lies in the rain shadow area, therefore the moisture feed during the southwest monsoons gets cut off by the Nilgiri hills. The only hope for Chennai then lies in the northeast monsoons. Skymet’s records show the highest yearly rainfall in the city has been recorded to be 2,570 mm in 2005.

But this is not the case every year. Major changes taking place in the global weather pattern have led to a massive decrease in the rain intensity and a dangerous increase in temperatures in India. The frightful Cyclone Nilam that hit south Peninsula in the last week of October destroyed life and property indeed, but luckily covered up for a feeble northeast monsoon this year. In spite of the heavy rains the cyclone brought, parts of south Peninsula still faced a rain deficit of about 56% (21% in south interior Karnataka, 35% in Kerala).

And although Chennai turned out to be luckier this year, the serious rain deficit had the cyclone not hit, concerned authorities, agriculturists and scientists. Skymet’s swift forecast of the weak rain in the south this year and the onset of the cyclone in the Bay of Bengal though alerted many farmers and their crops but weather forecasters say “this does not solve the problem permanently”, pointing out at the need to ideate some newer weather models by weather forecasting authorities and institutes in India, that could help in raising the alarm for the weather ahead, faster and more accurately. “Accurate forecasts will not just alarm the poor farmer about the monsoon condition and save his crop, but will also help the authorities to be prepared for the perennial flood situation during the cyclones or any inimical weather in Chennai and adjoining areas”, adds Mahesh Palawat, Head of the Forecasting team at Skymet Weather Services.

Photo by Emmanuel Dyan.