First rain brings chill, cleaner air

New Delhi: Delhi on Friday recorded the year’s first rain and the highest January rainfall in two years yet, leading to a sharp dip in temperatures and brief relief from elevated pollution levels.

The last highest rainfall in the first month of the year was recorded on January 30, 2023, when the city received 20.4 mm of rain, the India Meteorological Department (IMD) said.

Average rainfall recorded between 8.30 and 17.30 was significant, with Ridge receiving the highest at 17.4 mm, followed by Palam (14.0 mm), Lodi Road (13.4 mm), Safdarjung (13.2 mm) and Ayanagar (11.5 mm), indicating widespread light to moderate rain across Delhi NCR.

Rainfall activity was largely concentrated during the morning and early afternoon hours of Friday, with little to no precipitation recorded later in the day. Most stations reported light to moderate rain between 8.30 am and 2.30 pm, after which rainfall activity tapered off.

The showers led to a sharp fall in temperatures, with the maximum temperature at Safdarjung dropping to 16.0 degrees Celsius, which is 4.3 degrees Celsius below normal. This marked a steep fall from Thursday’s maximum of 27.1 degrees Celsius, when Delhi recorded its warmest January day in seven years.

Friday recorded the highest minimum temperature in four years as the mercury settled at 13.7 degrees Celsius, according to official data. The last time the national capital saw a higher minimum was on January 9, 2022, when temperatures dipped only to 13.8 degrees Celsius. The data available on the showers today indicated that the most significant spell occurred between 11.30 am and 2.30 pm. During this period, Ridge recorded 6.0 mm of rain, Safdarjung 4.6 mm, Mayur Vihar 3.5 mm, Ayanagar 2.5 mm, Lodi Road 1.6 mm, Palam 1.4 mm, and both Pitampura and Janakpuri 1.0 mm each. No rainfall figures were available for Pusa and Najafgarh. The minimum temperatures remained relatively high due to cloud cover and rain. Safdarjung recorded a minimum of 13.7 degrees Celsius, rising by about seven degrees Celsius from the previous day.

Across Delhi NCR, maximum temperatures stayed well below normal. Palam recorded 16.6 degrees Celsius, 3.6 degrees Celsius below normal, while Lodi Road logged 16.1 degrees Celsius, 4.9 degrees Celsius below normal. Ridge recorded 15.7 degrees Celsius and Ayanagar 15.8 degrees Celsius, both more than four degrees Celsius below normal, indicating persistently cool daytime conditions. Minimum temperatures were above normal at most stations. Palam recorded 13.0 degrees Celsius, Lodi Road 14.1 degrees Celsius, Ridge 13.7 degrees Celsius and Ayanagar 14.2 degrees Celsius, reflecting the impact of rain and sustained cloud cover. Visibility was affected during the morning hours. Safdarjung reported the lowest visibility of 600 metres at 10.00 am. For Saturday, the IMD has forecast a generally cloudy sky with shallow to moderate fog during morning hours. Minimum and maximum temperatures are likely to settle around 7 degrees Celsius and 17.0 degrees Celsius, respectively. “The minimum temperature is expected to dip further tomorrow due to today’s rainfall,” an IMD scientist said. For the highly anticipated Republic Day, the IMD has forecast no rainfall.

The rainfall brought temporary relief to air quality. After days of oscillating between severe and very poor, Delhi’s 24 hour average AQI stood at 282, placing it in the poor category.

As per the CPCB’s Sameer app, 15 stations were in poor, 20 in very poor, and four in moderate categories during the evening hours.