Rain, overcast skies in Delhi; heat wave unlikely till June 4

New Delhi: A fresh spell of rains, gusty winds and overcast skies turned weather pleasant in the national capital on Monday, with the India Meteorological Department's Regional Forecasting Centre saying heatwave conditions are unlikely to return to the capital till June 4.

Winds gusting up to 50 kmph swept the capital on Monday afternoon and several areas reported light rains, an IMD official said.

The Met office has issued a ‘yellow’ alert, cautioning people of traffic disruptions and inundation of low-lying areas.

The IMD uses four colour codes for weather warnings: green (no action needed), yellow (watch and stay updated), orange (be prepared) and red (take action).

The Safdarjung Observatory, Delhi's primary weather station, recorded a minimum temperature of 21.8 degrees Celsius, five notches below normal, on Monday. The maximum temperature is likely to settle 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 season. 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.

Delhi also witnessed an unusual episode of dense fog earlier this month. The minimum temperature dropped to 15.8 degrees Celsius on May 4, making it the third coolest May morning since the IMD started keeping records in 1901.

The city logged more than 20 mm of rainfall in April, the highest in the month since 2017.

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

The Safdarjung Observatory has not recorded any heatwave day this season so far.

The threshold for a heat wave is met when the maximum temperature of a station reaches at least 40 degrees Celsius in the plains, 37 degrees in the coastal areas, and 30 degrees in the hilly regions, and the departure from normal is at least 4.5 degrees.

According to the IMD, a fresh western disturbance will bring gusty winds, rain and even hail to some places on Monday and Tuesday. The maximum temperature is predicted to remain below the 40-degree mark until June 4.

Earlier this month, the weather office predicted below-normal maximum temperatures and fewer heatwave days in northwest India in May.