With 30 cm of rainfall, this May is Bengaluru's wettest ever

This May has turned out to be the wettest for Bengaluru in recorded history. The city received nearly 31 cm of rainfall, breaking a 66-year record.

With 30.1 cm of rainfall recorded in the city, it broke the longstanding record of 28 cm set in May 1957.

For every year since 2015, Bengaluru's May rainfall hovered above the mean monthly total rainfall of 128.7 mm, data from the India Meteorological Department (IMD) shows.

May rainfall averaged 18.5 cm in the last eight years. The highest rainfall was 27 cm last year and the lowest 13 cm in 2020 and 2021.

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The IMD’s seasonal cumulative rainfall data from March 1, 2023, to May 31, 2023, showed that Bengaluru city saw 343 mm of rainfall, 173 mm more than normal. The HAL airport recorded 275 mm and the Kempegowda International Airport 227 mm of rainfall.

From March to May, the Bengaluru Urban district has seen 245.8 mm of rainfall, 57% higher than the normal average of 156.1 mm in the pre-monsoon period. Bengaluru Rural has seen 131.5 mm of rainfall in the same period, a 6.5% decrease from the normal average of 140.7 mm.

The monsoon season from June to September sees an average of 60 cm of rainfall annually, with 11 cm in June, 12 cm in July, 16 cm in August, and September seeing the highest rainfall at an average of 21 cm.

A Prasad, who heads the meteorological centre at the IMD, explained what caused the record-breaking rainfall.

"The moisture retention in the wind has been very high. On most days, wind discontinuity or trough at 900 metres above mean sea level prevailed or passed through Karnataka, causing wind convergence and promoting convective activity. This has led to more thunderstorm days with one or two intense spells in the city in May," he stated.