It takes a lot to remove Chennai Heat during the month of April but “The Great Chennai Freeze” has actually managed to do that since last year thanks to an article from The Hindu. It appeared on 17th April 2015 and talked about how Chennai could possibly have received snow a good 200 years back during April 1815 thanks to the Volcanic Eruption of Mt. Tambora in Indonesia.
The article talked of temperature dropping to 11 degrees on April 24th 1815 and four days later Chennai managed to actually record sub zero temperatures. For the people of Chennai who have long been identified with famous Chennai heat it gave an opportunity to get back at all those who made fun of the Chennai heat, they managed to Retweet & Share in droves without battling an eyelid and wondering for even a second if there was any merit in what was written. Whether it was because the original article appeared in The Hindu or “The Great Chennai Freeze” with possible snow was too romantic to think logically average Chennaites decided it was an opportunity not to be missed. As they say History repeats itself 17th April 2016 saw once again the same mad frenzy appear everywhere with people once again showing their fondness to the Chennai Freeze. The Hindu Article took a lot of reference from this Book which for some strange reason did not feature any official temperature records but just hear say evidence from various mariners. It carried a period map which looked fairly accurate on first glance on how a volcanic eruption in Indonesia could have influenced Madras.
COMK was the only dissenting voice last year when we put this article explaining how the circumstantial evidence indicated in the original Hindu Article should not be taken on face value. But Alas in the madness of Chennai Freeze sane voice never gets the same bandwidth. While last year we relied on circumstantial evidence ourselves to indicate the event may not have happened. But this year’s much larger frenzy provoked us to double our efforts in understanding the truth.
Thanks to John Goldingham, the first official astronomer of Madras Observatory, who meticulously maintained the meteorological observations now we can say with conviction the Great Madras Freeze of 1815 did not happen. Given below is the Hourly Temperature observations of March & April 1815 as recorded by J Goldingham which clearly indicates what was the actual wet bulb temperatures during 1815 April the period of so called Chennai Freeze. The approximate corresponding dry temperature which we all know off today should have been around 30 degrees to 40 degrees depending the humidity that prevailed during that time at Madras. Open the image in new tab for higher resolution.
Further proof can also be found in the book Sketches of Most Prevalent Diseases in India by Sir James Annesley, originally published in the early 19th century, had carried the monthly mean temperatures for the period 1815 to 1820 at Madras based on Goldingham’s data. The mean temperature of April 1815 was actually the highest during this period effectively confirming the Big Chennai Freeze did not happen as it would have skewed the monthly mean temperatures drastically for April 1815.
Chenoweth who has put out a very well researched article on the “Year Without Summer” based on the Log Books of various ships that plied around the oceans during that period. The article possibly indicates it could have been a La Nina episode along with the volcanic eruption that had resulted in some reduction in temperatures across the globe but certainly not a freeze as many believe
It is unfortunate that a reputed newspaper like The Hindu decided to carry a story based on a book without going the extra yard to verify the weather data which possibly is available with IMD even today based on Goldingham’s original observations. The Myth of Great Chennai Freeze is now the Frankenstein of this parts of the world.
Edit: New developments that was added on 1st May based on further study.
These include study by Dr. Chenoweth who had used the temperature data of Dr. Goldingham
and had used the Madras temperature graph as part of his study on 1815 eruption. He has taken the data from the original manuscripts available at the Royal Meteorological Society. 
This study from Dr. Chenoweth does not mention any abnormal temperature decrease in Chennai due to the Mt. Tambora explosion nor does he cast any aspersion on the original data published by Goldingham.
The Asiatic Journal that was published in 1816 also has a section on the Meteorological data from Fort. St. Geroge observed over the previous months which does not indicate any abnormal temperature pattern during the referred period 
And finally the source of the Great Madras Freeze which was included by Dr. Stothers as a reference and not part of his main study. 1816 Asiatic Journal which has no reference to who wrote this particular bit nor any supporting confirmation from elsewhere.
