CHENNAI: As Chennai swelters through the hottest days of May, citizens have been looking skywards for those pre-monsoon thundershowers that give them respite for a day or two. On an average, Chennai has two such rainy days in May. But this year, there have been none, as per the met records.
In fact, Chennai is the only district in Tamil Nadu that is yet to receive a drop of pre-monsoon rainfall, according to Regional Meteorological Centre data.
Neighboring districts Kancheepuram and Thiruvallur are little better. Both have had rainfall in traces since March 1. Kancheepuram has received only 10.7 mm from March 1 to May 23rd while Thiruvallur received 11.9 mm.
Pre-monsoon showers over Tamil Nadu are normally caused by the development of low pressure areas over the Bay of Bengal. Last year, a depression in the western Bay of Bengal intensified into a cyclone and brought three days of heavy rainfall over Chennai mid-May. No such low pressure system has materialized this year, and therefore it’s been Chennai’s lot to sweat it out.
Further, relative humidity has been less in Chennai this May compared to March and April. The average humidity for the first three weeks of the month was 63 per cent. At noon Tuesday, humidity was as low as 33 per cent in Ambattur. Normally, in the days preceding a thunderstorm, relative humidity inches above 90 per cent along with a sudden drop in temperature.
The forecast for Chennai for the next few days indicates an average of less than 60 per cent humidity for the rest of the month, while the temperature is expected to remain above 37 degrees Celsius.
In Chennai, the lack of even a trace of moisture comes at a time when the city is battling a record summer. According to Accuweather, temperature in the city stayed above the 40°C mark on eight days during the first three weeks of May. Last year, there were a five plus-40 days, punctuated by those Bay-induced rains.