Monsoon has ended its Calcutta innings three days before Puja with a curious scorecard of deficit and surplus that made this the city’s most unusual rainy season in many years.
Although the withdrawal of the monsoon trough on Tuesday doesn’t rule out rain triggered by local conditions, weather scientists say there’s little chance of the city’s date with celebration this year being interrupted by a shower or two.
“Based on data from the last three years, the temperature varies between 23.9 and 33 degrees Celsius between October 20 and 24. Relative humidity ranges between 54.7 and 95.5 per cent and there’s no rain,” a Met official said.
The rain statistics for the season, of course, suggest it would be wiser to bet on the colour of your pretty neighbour’s Ashtami attire than the Calcutta weather.
June, July and August, which are supposed to bring rain in torrents, saw a deficit of 38.5, 38.2 and 23.3 per cent this year. September, when the rain count usually tapers off, saw a surplus of 41.1 per cent and October exceeded all expectations by logging a first-fortnight surplus of 135.7 per cent.
“In the final analysis, monsoon’s performance has been satisfactory. It started sluggishly but gathered momentum in the last phase and went out on a high,” said Gokul Chandra Debnath, the director of the Regional Meteorological Centre in Alipore.
The rearguard action helped the season finish with an overall deficit of 19 per cent in terms of rainfall across south Bengal, which meteorologically falls in the “normal” range.
“The monsoon trough usually withdraws between October 12 and 15 and so the timing of its departure this year is normal as well,” Debnath said.
The turnaround began mid-August and the rain that had eluded the city for so long kept pouring at frequent intervals until last week.
October brought 186mm of rain in its first fortnight, which is 22mm more than the normal rainfall usually received through the month (based on data from 1971 to 2000).
The monsoon trough had reached the city on July 17, nine days behind schedule. It rained 34mm that day, the highest over 24 hours in the whole of June, July and the first 10 days of August.
On most days during the lean period, the skies would be cloudy but produce little rain.
Met officials attributed the unusual monsoon to fewer cyclonic circulations forming this year. “Such circulations are needed to supplement the monsoon trough,” a weather scientist said.
Hotel management student Sucheta Mukherjee said she would happily forget her “monsoon woes” if the weather remained pleasant without any rain this Puja.
She could be speaking for all of Calcutta.