Suburbs of Chennai have been growing warmer by every passing decade and the average annual maximum temperature has increased in the city over the past five decades.
A study done by Chennai Rains / Chennaiyil Oru Mazhaikalam, a weather blogging site, found that the city’s suburbs are experiencing warmer winters too and the average daytime temperature during January and February is on the upward trend. The study was carried out based on the data of India Meteorological Department sourced from National Climatic Data Centre, U.S. archive of weather data.
Analysis of the data of the weather station in Meenambakkam revealed that the average decadal maximum temperature has increased from 33.1 degrees Celsius to 34.5 degrees Celsius over the past five decades since 1973.
Moreover, it was observed that the average yearly day temperature had been more than 34 degrees Celsius since 2010 indicating that the suburbs were becoming warmer. During the previous years, the average annual maximum temperature had been above 34 degrees Celsius only during eight years between 1973 and 2010.
Similarly, the average maximum temperature during January and February has climbed up from 29.8 degrees Celsius to 31.1 degrees Celsius over the past five decades.
K. Srikanth, who runs the Chennaiyil Oru Mazhaikalam blog, said it had been observed that there had been a pattern of steady rise in temperature level through various seasons. Northeast monsoon contributed the most in the trend of warmer temperature in the city with average maximum temperature in October and December being 31.6 degrees Celsius, which is 1.7 degrees Celsius higher than the average temperature experienced in the past 50 years.
“We have to study about aspects of localised urban heat island effect and global scale impact. The prolonged dry weather leading to an increase in maximum temperature and short bursts of intense rainfall could be possible factors,” he said.
However, the data revealed that the summers were relatively cooler in the city’s peripheral areas. The increase was marginal by 0.7 degrees Celsius during summer months. This trend too needed a deeper study. The impact could be more pronounced in the core city, Mr. Srikanth added.