A day after Delhi recorded its hottest May day in two years — at 44.4°C —the Met department had some cool news for Delhiites.
The weatherman predicted that the day temperature would drop by a few degrees and hover around 40 degrees Celsius for the next seven days, with thunderstorms expected almost every day this week.
The Capital witnessed its hottest day since 2015 on Monday, with the mercury settling at 44.4 degrees Celsius at Safdarjung. The temperature at Palam was a degree hotter.
“We expect the temperature to drop by a few degrees over the next few days as thunder storms are expected to hit the city,” said a senior official of the regional weather forecasting centre.
Met officials explained that a western disturbance is expected to trigger some thunderstorms and dust storms by Wednesday night. A cyclonic circulation was developing over Delhi–NCR too that was likely to result in more such developments later in the week.
“These developments will help cool down the air at higher altitudes. Convection currents would then allow the colder air mass to come down to lower levels. As a result of this, the mercury level is expected to plummet to around 39 degrees by the end of the week,” said a Met official.
The nights, however, are likely to remain hotter than normal as cloudy skies will not allow the land to radiate the heat even after sunset.
“Usually May and June are the hottest months in Delhi with day temperatures often shooting above 45 degrees Celsius. If we consider the climatic normal which is an average of monthly temperatures over a period of three decades, May is the hottest month in Delhi followed by June,” said an official.
The mercury had shot up to 45.7 degrees on May 20, 2013 – the highest this decade. The hottest day in the month of May which Delhi has ever experienced was in the year 1944 when the temperature touched 47.2 degrees Celsius.
But during some years the mercury shoots up more in June than what it was in May. In 2014 while the temperature had shot up to 43.7 in May, it had touched 45 in June.
But interim reliefs triggered by western disturbances and cyclonic circulations in the summer months, help to keep the rising mercury under check.
Without such checks the mercury shoots up and results in spells of heat wave. Heat wave is a condition when the maximum temperature shoots up beyond the 40 degree Celsius mark and is around 4 – 5 degrees above the climatic normal. If it goes seven degrees above the climatic normal it is called ‘severe heat wave’.
A few heat waves have already swept the city since April when the day temperature started hovering above the 40 degrees Celsius mark.