Yet another heatwave to hit city in a week
The Pakistan Meteorological Department has warned of yet another severe heatwave within a week, even before the ongoing spell, which has kept temperatures between 42 and 44 degrees Celsius over the past five days, has come to an end.
“Karachiites will have a very few days of respite from the hot weather in the ongoing month of Ramzan as the possibility and chances of another severe heatwave by the end of the current month or start of June are very high,” Dr Ghulam Rasool, the director general of the PMD told The News on Wednesday.
Temperature remained above 43 degrees Celsius on Wednesday in the city under the influence of dry and hot winds from the North and North Westerly directions, which have gripped the city since Saturday when low pressure areas in the Arabian Sea and climatic conditions in the region deprived Karachi of its cooling system – the pleasant sea breeze that brings down the temperature in the summer evenings.
Fortunately, no heat-related deaths have been officially reported during the ongoing heatwave despite it being the month of Ramazan, most probably due to the lack of humidity in the air and growing awareness among people. In June 2015, a deadly heatwave that hit during Ramazan left thousands of people dead in the city in similar weather conditions.
Since March, Karachi has witnessed three heatwaves this year and weather experts said chances of a few more heatwaves were “very likely”, one of which could strike within a few days after the end of ongoing one.
“For the last few years, the temperature of the Arabian Sea is on the rise and frequency of low pressure areas formation has increased in the summers,” said Rasool. “These low pressure areas cut off the sea breeze towards the coast, especially towards Karachi, and under the influence of warm and dry winds, Karachi’s temperature starts shooting.”
The PMD chief said that although nobody had died due to hot and dry conditions during the last three spells as humidity levels in the air remained very low, reducing chances of heat stroke, nobody could predict if the upcoming heatwave would be as benign as the previous ones.
“In this scenario, I would request people and the state organisations to remain on high alert in the coming months. Keep warning people to adopt precautionary measures to protect themselves from heat stroke and start adapting to the changing climatic and weather conditions,” he advised.
Urban heat island effect
The urban heat island effect is another cause of concern in Karachi. In the absence of sea breeze for several days, the city’s temperature remains hot even in the night as the trillions of tons of concrete which traps heat during the day, starts radiating the heat in the night and there is no respite for the people during the day and night for several consecutive days, experts said.
It was the urban heat island effect which resulted in the thousands of deaths in 2015’s heatwave when the city was deprived of sea breeze because of a low pressure area in the Arabian Sea and warm winds trapped in the port city for several days kept the temperature as high as 46 degrees, with a ‘real feel’ of 52-55 degrees Celsius due to high humidity in the air. “There is an urgent need to stop constructions in Karachi and bring an end to city vertical and horizontal expansion,” said environmentalist Nasar Usmani. “Now this city needs more trees instead of more buildings and concrete structures.”
Warning Karachiites that Thursday would also be a hot and dry day with temperature soaring to 43 degrees Celsius, Karachi Met Office Director Abdur Rashid said sea breeze would resume from Friday and there would be a few days relief from the heat.
He said temperature remained 43.2 degrees Celsius on Wednesday, adding that they were expecting another warm and dry day on Thursday under the influence of the current heatwave which compounded by prolonged power outages has made the lives of people miserable for the last few days.