Warmest December in 20 years at Chennai

Weather Update

As the new year festivities wind down and the rains start easing it is that time of the year when Chennai starts seeing its best weather with winter conditions establishing. Many might say Winter in Chennai is an Oxymoron, but ask the weather watchers of Chennai they will defend the Chennai Winter to their death.

Nice nippy mornings that are extremely pleasant without the need to bundle oneself with multiple layers of clothes. Fairly pleasant day time conditions that is warm enough to allow you your regular routine without any hindrance but not hot enough to make it uncomfortable. Just like Chennaiyil Oru Mazhaikkaalam, Northeast Monsoon, our winters are also special for us.

It is for this we keep a track on weather irrespective of whether rains are on the horizon or not after Northeast Monsoon starts winding down. Without doubts wind pattern certainly plays a key role in modulating temperatures over Chennai. It is for this reason technically winter in Chennai starts once the Northeast Monsoon winds down completely. Though one should not ignore the fact that even during Northeast Monsoon time temperatures dip when overall drier atmospheric conditions are prevailing and the Northerlies take control rather than Easterlies. Like 2016 which saw Chennai AP record sub 20°C day as early as 27th Nov. But occasionally we might have a 2006 – ’07 type year which did not dip below 20°C right through the winter with December seeing only 20.1 mm rainfall. Ironically only 20.1 mm was recorded during December that year.

It is in this context we have to look at Minimum Temperature pattern of December 2019. While one can always go back any number of years while trying to create temperature records we need to keep in mind the overall climate keeps evolving so it makes sense to restrict to a few decades while trying to understand patterns at local levels.

  • For the first time in two decades Chennai AP has seen a December where the average minimum temperature has crossed 23°C for the month
  • Similarly the lowest temperature recorded during December is again the highest in these two decades. As a matter of fact 1997 December recorded 21.9°C as the lowest for the month. 1997 saw one of the best NEMs for Chennai and December had nearly 13 rainy days (<2.5mm) at Chennai AP. With an average min. temp of 23.5°C for the month 1997 warmest Dec. in recent times.
  • Most of the year Chennai sees the first dip in temperatures around 3rd week when Northeast Monsoon starts waning away. December more often than not sees its coolest night around Christmas period.
  • As things stand we are unlikely to see the first sub 20°C in the next few days so in all probability we might see the first sub 20°C day of the winter for Chennai around Pongal time.