scorecardresearch
Follow Us:
Thursday, December 09, 2021

Delhi sees heaviest October rain in 65 years

The rain and strong winds also bring down the city's AQI to good -- the first time in this year.

By: Express News Service | New Delhi |
Updated: October 19, 2021 2:16:49 am
Delhi rainAccording to data shared by the India Meteorological Department (IMD), Delhi has received 94.6 mm of rain in October so far, the highest in 65 years. (Express photo by Prem Nath Pandey)

Heavy rainfall over Sunday and Monday morning has made October in Delhi the rainiest since 1956.

According to data shared by the India Meteorological Department (IMD), Delhi has received 94.6 mm of rain in October so far, the highest in 65 years, when 236.2 mm of rain was received in the whole month. The 24-hour accumulated rainfall – 87.9 mm – is also the highest in 65 years, data shows.

The heavy rain also gave the Delhi its first ‘good’ air quality day this year. The AQI on Monday, calculated by the Central Pollution Control Board, stood at 46. On Sunday, the air quality as a 24-hour average was in the ‘poor’ category. Because of the rain and strong wind, the primary pollutants on Monday were Carbon Monoxide and PM 10, while on Sunday they were PM 2.5 and PM 10.

Explained

Winter pollution

Winters in Delhi are especially polluted since it is the driest period in the city. Wind speeds also dip to their lowest in winters. Low temperatures and humidity also aid the accumulation of pollutants, which means that winters in Delhi bring ideal conditions for pollution to rise.

The temperature on Monday dipped significantly too. The maximum, (recorded during the afternoon) was 23.9 degrees Celsius – a staggering nine degrees below normal. The minimum, recorded early morning, was only a few degrees lower at 20.1 degrees Celsius.

Weather has a significant role to play in Delhi’s air quality, which, along with its internal sources of pollution such as dust and vehicular emissions, is affected by dust storms originating as far as the Middle East and paddy stubble burning.

Strong winds aid the dissipation of pollutants which are accumulated in the region, while rains help ground them. Winters in Delhi are especially polluted since it is the driest period in the city. Wind speeds also dip to their lowest in winters. Low temperatures and humidity also aid the accumulation of pollutants, which means that winters in Delhi bring ideal conditions for pollution to rise.

According to IMD officials, a western disturbance over southern Afghanistan and easterly winds over northwest India are behind the rains in the city. In addition, the interaction between two low-pressure systems – one over Bay of Bengal and the other over the Arabian Sea – has brought rain to several parts of the country.

Scientists at the System of Air Quality and Weather Forecasting and Research (SAFAR) have forecast another ‘good’ air quality day on Tuesday as well as moderate winds are expected to continue.

📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay updated with the latest headlines

For all the latest Delhi News, download Indian Express App.

  • Newsguard
  • The Indian Express website has been rated GREEN for its credibility and trustworthiness by Newsguard, a global service that rates news sources for their journalistic standards.
  • Newsguard
Advertisement
Advertisement
Advertisement
Advertisement