Mercury surges above normal in Bengaluru as westerlies linger; rain likely from April 11

Bengaluru: The mercury surged sharply in Bengaluru on Wednesday, rising more than 2°C above normal at the city's base weather station. However, relief may be around the corner, with the weatherman forecasting rainfall from April 11 onwards. 

At 5.30 pm, the maximum temperature in Bengaluru City was 35.2°C, about 2.2°C above normal. The HAL airport and the Kempegowda International Airport (KIA) each recorded 35°C, an increase of 1.3°C and 0.3°C, respectively. For Bengaluru City and HAL airport, this was the highest maximum temperature recorded this month, according to the India Meteorological Department (IMD). 

N Puviarasan, Scientist 'F' and Head of Meteorological Centre, IMD, Bengaluru, told DH that westerly winds in the morning were causing dry weather and clear skies during the day, pushing up the mercury. 

Westerly winds during April tend to be warm and dry, causing daytime temperatures to rise above normal. They also limit cloud cover and suppress convective (cooling) rainfall. Increased concretisation and traffic jams in Bengaluru make the heat more intense. 

The IMD official noted that dry weather would prevail all over Karnataka for the next two days before daytime temperatures begin to fall around April 11-12. Bengaluru will likely see rainfall in the evening, he added. 

While the maximum temperature is expected to hover around 35°C in the coming week, the city is likely to see cloudier skies, which could cap daytime temperatures. 

April has historically been the hottest month for both Bengaluru City and HAL airport weather stations, with mean maximum temperatures of 34.1°C and 33.8°C, respectively. The highest-ever maximum temperature for Bengaluru City was 39.2°C, recorded on April 25, 2016. The HAL airport's highest-ever maximum temperature was 38.3°C, recorded on April 14, 1960, according to the IMD. 

Bengaluru receives pre-monsoon thunderstorms in April, usually in the evenings. The Bengaluru City weather station gets four rainy days on average in the month, translating to 61.7 mm of rainfall. The HAL airport gets 3.5 rainy days on average in April, bringing in 59.8 mm of rainfall