With 101mm rain, Delhi logs its coolest June since 2008

Delhi ended June with a monthly average maximum temperature of 37 degrees Celsius (°C), making it the coolest June since 2008 when the monthly average maximum was 35°C, India Meteorological Department (IMD) data on Friday showed.

This was largely down to light to moderate showers being recorded through the month and the early arrival of the southwest monsoon, which ended Delhi’s monthly total rainfall for June at 101.7mm — its highest since June 2017, when 191.9mm was recorded.

“In terms of the average monthly maximum, this is the coolest June since 2008. The temperature was regulated by light spells of pre-monsoon rain in the first half of the month and we have seen significant activity in the last week, since the arrival of the monsoon on June 25,” said Kuldeep Srivastava, scientist at IMD.

The average monthly maximum of 37°C was two degrees lower than the long-period average (LPA), which stood at 39°C. Delhi’s average monthly minimum, meanwhile, was clocked at 25.9°C, which was 1.8 degrees lower than the LPA of 27.7°C. This was also the second consecutive month that over 100mm of rain was recorded, with 111mm recorded in May.

The long spells of rain also brought down the city’s maximum temperature on Friday to 34.5 °C, which was three degrees below normal for this time of the year. The minimum was clocked at 25 °C, which too was three degrees below normal.

In comparison, the maximum on Thursday was 34.2°C, which was three degrees below normal. The minimum was recorded at 23.8°C on Thursday, which was four below normal.

Meanwhile, IMD issued a “yellow alert” for Delhi, even as more rain is expected throughout the week. Forecasts for the next six days show light rain is expected to continue in Delhi NCR till July 6, with chances of moderate rain on July 5 and 6. “A yellow alert is in place for moderate rainfall on July 5 and 6. Before that, most places will receive drizzle to light rain,” an official said.

Rain was recorded on 17 days this month at Safdarjung — representational of Delhi’s weather, including Friday, when rain was recorded throughout the day. The highest single-day rainfall spells this month happened between June 24 and 25, when 48.3mm was recorded in the Capital. The arrival of the southwest monsoon was subsequently declared in Delhi on June 25, which was two days earlier than its normal date of June 27.

While 5mm of rainfall was recorded in a 24-hour period till 8.30am on Friday, another 26.9mm of rainfall was recorded in the next nine hours between 8.30am and 5.30pm.

However, this 26.9mm will now be counted in July’s rainfall total, as the IMD only considers the monthly rainfall till 8.30 am on the last day of the month. IMD data also showed there were only five days in the month — June 9, 10, 12, 13, and 14, when the maximum was 40°C or higher.

“A majority of these rain spells occurred overnight or in the early hours of the day, which kept the maximum temperature in check. Overcast skies would then prevail for the remainder of the day, ensuring that the maximum stayed below normal on most days,” Srivastava added.

Five of the six months so far this year have seen excess rainfall, Met officials said, adding that Delhi received 20.4mm of rainfall in January which was an excess of 7% over the LPA of 19.1mm.

February was an anomaly, with no rain being recorded throughout the month. In March, there was an excess of 206%, with 53.2mm of rainfall being recorded against the LPA of 17.4mm. In April, 20.1mm was recorded against a normal mark of 16.3mm —an excess of 23%. In May, the 111mm rainfall made it Delhi’s fourth wettest May for Delhi between 1991 till 2023, with an excess of 262% over the monthly normal mark of 30.3mm.

A second Met official said this has been an unusual summer, with more pre-monsoon showers being recorded, largely led by more western disturbances than usual.

“June’s rainfall total was still below 30mm, but the early arrival of the monsoon took it into surplus. We will continue to receive more rain at the start of July too,” the official added.