NEW DELHI: The national capital received 87.9 mm rainfall over the past 24 hours — the highest single-day rainfall recorded in October in 65 years and the fourth-highest since the record keeping began, said the India Meteorological Department (IMD) on Monday.
The record spell washed skies of pollutants leading to a massive drop in the air quality index (AQI) that read 46, resulting in the first ‘good’ air day recorded in Delhi this year. According to the IMD data, the Safdarjung Observatory, considered representative of Delhi’s weather, the city received 87.9 mm rainfall over 24 hours (8.30 am on Sunday to 8.30 am on Monday). Also, it was the fourth-highest 24-hour rainfall received during this month since 1910 (The time when rain records started being kept) when 152.4 mm rain was recorded during this period.
Data shows that between 1910 and 2021, such heavy 24-hour spell in October was seen only twice — in 1956 when 111 mm was received and in 1954 when 172.7 mm rain was received. According to the IMD, October has so far received 94.6 mm rainfall this month, which is the fifth-highest monthly rainfall for the month since 1910. Previously, 93.4 mm monthly rainfall was recorded during this month in 1960, 236.2 mm in 1956, 238.2 mm in 1954 and 185.9 mm in 1910.
“A good spell of rain during this month is uncommon, in particular, in the northwest region. The heavy spell was mainly a result of two low-pressure systems being formed — one over the Bay of Bengal and another over the Arabian Sea. Also, there was a Western Disturbance, which interacting with the low-pressure systems resulted in rainfall in parts of the northwest region including Delhi and adjoining areas,” said a senior IMD official.
However, the moisture-laden easterly winds are likely to change to westerly winds from Tuesday onwards marking an end to the rain activity, the official added. Independent weather experts too said that such spells are rare and not good for the ecology. “These are unseasonal rains, which can damage crops during the harvest season. The wind direction will change from easterly to north-northwesterly from October 19 onwards. This will also lead to a gradual increase in pollution levels in Delhi,” said Mahesh Palawat, vice-president, Skymet, a private weather forecaster.
