The heaviest one-day rain in August in 47 years in Mumbai, home to India’s financial markets and the central bank, inundated large parts of the mega city and disrupted businesses and services.

The Colaba weather station recorded 33.2 centimeters (13 inches) of rainfall in the 24 hours through 8:30 am Thursday, the highest downpour for a single day in August since at least 1974, according to the India Meteorological Department. More spells of moderate to heavy rainfall are forecast for Thursday, accompanied by strong winds of as much as 80 kilometers per hour.

“It’s not a very regular thing” to witness intense showers continuing for several days, K.S. Hosalikar, deputy director general at the weather department’s Mumbai center, said late on Wednesday.

Heavy showers in the city may hamper its fight against the coronavirus pandemic. Mumbai is among the worst affected cities in the country, which has more than 1.8 million confirmed infections and close to 40,000 deaths.

Authorities asked residents to stay indoors even as several offices are shut with employees working from home due to coronavirus-related lockdowns. As many as three crandes collapsed at Jawaharlal Nehru Port Trust on Wednesday, but no one was injured.

Disruptions due to rains, which often flood roads and low-lying areas, are a regular occurrence in Mumbai during the monsoon season, as authorities in the mega city of 18 million grapple with crumbling infrastructure.

The Santacruz weather station recorded 16.2 centimeters of rainfall in the 24-hour period that ended at 8.30 a.m. on Thursday. The center witnessed 26.9 centimeters of showers in the 24-hour period by Aug. 4 morning, while Colaba got 25.2 centimeters, according to the weather office.