Thunderstorm, rain bring relief from heat in Delhi; 10 flights diverted

A severe thunderstorm reaching speed up to 80 km per hour and rain hit the national capital on Tuesday evening, affecting vehicular movement and leading to diversion of many flights.

The India meteorological department said another western disturbance is likely to bring storms and rain to the northern plains, including Delhi, over the next few days.

Maximum temperatures are predicted to remain below the 40-degree mark until June 5.

The Safdarjung Observatory, Delhi's primary weather station, on Tuesday recorded a maximum temperature of 35.9 degrees Celsius, five notches below normal.

Delhi experienced moderate to severe thunderstorms with lightning and gusty winds, reaching speed of 70-80 kilometres per hour, the Met office said.

As gusty winds blew across the city, many pedestrians rushed for shelter as it began to rain while vehicular traffic was also affected.

"Due to bad weather in Delhi, 10 Delhi-bound flights were diverted (nine from Jaipur and one from Lucknow) between 6:25 pm and 8 pm," an airport official said.

The weather office has issued a 'yellow' alert for Wednesday, warning of traffic disruptions and inundation of low-lying areas due to rain. The maximum temperature is expected to hover around 35 degrees Celsius.

May, historically the hottest month in Delhi with a mean maximum temperature of 39.5 degrees Celsius, has recorded below-normal temperatures and excess rain this time.

Meteorologists attributed the phenomenon to higher-than-usual western disturbances -- weather systems that originate in the Mediterranean region and bring unseasonal rainfall to northwest India -- this pre-monsoon season (March to May).

"Usually, five to six western disturbances are recorded in the northern plains in April and May. We saw 10 western disturbances, mostly strong ones, this time," said Kuldeep Srivastava, head of the Regional Forecasting Centre, IMD.

Delhi recorded maximum temperatures above the 40-degree mark for just nine days in May with heatwave conditions affecting some parts for two days.

According to IMD data, the Safdarjung Observatory has so far recorded 86.7 mm of rainfall in May. On average, the national capital logs 19.7 mm of rainfall in the whole month.

The city logged more than 20 mm of rainfall in April, the highest in the month since 2017, and heatwave conditions at isolated pockets.

Overall, Delhi has gauged 158 per cent more rainfall -- 161.2 mm against a normal of 62.6 mm -- during the pre-monsoon period this year.