After relatively dry summer, Delhi pins hopes on a plentiful monsoon

It has been a relatively dry summer for Delhi, since the Capital received only 72.5mm of rainfall between March 1 and June 26 compared to the usual 113.3mm from March to June. The deficit might reduce a bit if it rains in the next few days.

Delhi is expected to be hot and humid on Monday, with some drizzle and light rain expected in the next two days, the weather bureau predicted, as it issued a yellow alert for Tuesday, anticipating thunderstorms and gusty winds.

It did not rain at all in March and precipitation in April was a minuscule 0.3mm. This was in sharp contrast from the excess rainfall in the past two years. Delhi recorded 186.2mm of rainfall in 2021 and 229.5mm in 2020.

In 2019, however, rainfall in these four months was even lower at 59.8mm, according to India Meteorological Department data.

Although the weather office is yet to say when the monsoon will arrive in Delhi, it is expected to be a few days later than June 27, the usual date of onset. Light rain and drizzle may occur in parts of Delhi on Tuesday, the Met office has said, though the monsoon is set to advance further towards the Capital.

“It is difficult to say when the monsoon will touch Delhi,” said RK Jenamani, a scientist at the weather office. “Depending on the progress over these next three to four days, an assessment for Delhi can be made.”

While there have been a few western disturbances this summer, a majority have been inactive. Western disturbances often lead to showers in the city.

“In March and April, there was no active western disturbance, and in May, where we saw some decent spell of rains, two were active,” Jenamani said. “In June so far, there was no western disturbance in the first 15 days, and we have only seen one active spell this month, which occurred around June 16 till 20.”

The southwest monsoon will arrive in Delhi any time after June 28, according to private forecaster Skymet Weather Services. “Rains will return from June 28 onwards and there will be rainfall on both June 29 and 30, as well as on July 1 and 2, so it is possible that the onset could be declared during this period,” said Mahesh Palawat, vice president at Skymet. It had earlier forecast the monsoon to reach Delhi by June 30.

In 2017, Delhi received 270.4mm of rainfall, nearly 2.5 times normal, between March and June. In 2012, it just received 43.2mm in that period.

Delhi usually sees most of its rainfall in July, August and September. The average in these three months total 583.4mm.

Last monsoon, it received 1,134.9 mm during this period, an excess of around 95%.

Delhi earlier received excess rainfall in the winter months of January and February, with 88.2mm recorded in January, nearly four times the normal of 21.7mm, while it was 29.7mm in February, 1.5 times higher than the monthly average of 18mm.

The Capital recorded yet another hot and humid day, with most parts recording a maximum temperature in excess of 40 degrees Celsius. While Safdarjung, the base weather station, saw a high of 40.6°C on Sunday, three notches above normal and marginally higher than Saturday’s maximum, Delhi’s hottest location was Najafgarh, where it touched 42.4°C. Delhi’s relative humidity oscillated between 49% and 69% over the past 24 hours, IMD said.

In terms of minimum temperature, Delhi had a low of 29.0°C, one degree above normal for this time of the year, and 4.7 degrees higher than Saturday’s minimum.

High temperature and humidity will continue in the Capital on Monday, with chances of thundery development, but no significant rain.

The maximum is likely to be around 40°C, and the minimum will be around 29°C, according to the Met’s forecast.

On Tuesday, IMD has forecast light rain and drizzles in parts of Delhi, with the majority of rain activity expected from Wednesday.

“The major rain activity will be seen from June 29 onwards. This will largely be light rainfall. We have issued a yellow alert primarily due to thunderstorm activity, with gusty winds of 30-40km per hour expected on Wednesday,” said Jenamani. “There will be similar weather on Thursday.”

IMD issues a ‘yellow’ alert to warn the general public of a weather-related phenomenon, in this case, the high possibility of heatwave to severe heatwave conditions occurring across Delhi.