This is for the second time this month that Mumbai has recorded the highest maximum temperature in the country.
Senior IMD scientist R K Jenamani said the monsoon covered south and central Arabian Sea, entire Kerala, parts of Karnataka and Tamil Nadu between May 31 and June 7.
Delhi's minimum temperature on Wednesday morning plunged to 4.4 degrees Celsius -- the season's lowest -- making the national capital colder than Dharamsala, Nainital and Dehradun.
Delhi is likely to receive the first monsoon showers on June 30 or July 1, India Meteorological Department (IMD) officials said on Tuesday.
Western disturbances are near Pakistan-Afghanistan and are moving towards Delhi and thunderstorms or dust storms are likely to be experienced in northwest India, senior scientist at IMD RK Jenamani told ANI.
The city has been witnessing heavy rains since Tuesday night, resulting in water logging in many areas.
The mercury breached the 46-degree Celsius mark in several places such as Allahabad (46.8 degrees Celsius) and Jhansi (46.2 degrees Celsius) in Uttar Pradesh; Sports Complex (46.4 degrees Celsius) in Delhi; Ganganagar (46.4 degrees Celsius) in Rajasthan; Nowgong (46.2 degrees Celsius) in Madhya Pradesh; and Maharashtra's Chandrapur (46.4 degrees Celsius).
A record 119.3 mm rainfall pounded Delhi under the impact of cyclonic storm Tauktae and a western disturbance in 24 hours ending 8:30 am on Thursday, breaking all the previous records for May, the IMD said on Thursday.
The city also recorded a maximum temperature of 23.8 degrees Celsius, 16 notches below normal and the lowest in the month of May since 1951, the IMD said.
Skies over Delhi hung heavy with smoke and its air quality inched towards "severe" category on Diwali night as people burst firecrackers in a blatant disregard to the government's ban against it, imposed amid an increase in the contribution from farm fires.
IMD said on Tuesday that the cyclone has a wind speed of 100-110 kmph and gusting to 120 kmph. The coastal areas of Tamil Nadu are expected to receive heavy rain between November 23-26.
The neighbouring cities of Faridabad (469), Greater Noida (464), Ghaziabad (470), Gurgaon (472) also recorded 'severe' air pollution levels.
Normally, monsoon reaches Delhi by June 27. It covers the entire country by July 8. Last year, the wind system had reached Delhi on June 25 and covered the entire country by June 29.
A day after Cyclone Yaas tore through coastal Odisha and Bengal to cause havoc as far as Jharkhand, tornadoes, torrential rains, bridge collapses and swelling rivers continued to plague eastern India as people tried to pick up their lives amid the debris of swept away mud homes and swamped farmlands.
The IMD has also issued a red-coded warning alert to the Odisha and West Bengal coasts.
West Bengal and Odisha have evacuated lakhs of people from vulnerable areas to safety as severe cyclonic storm 'Yaas' is nearing the coast and is expected to make landfall near Dhamra Port in Bhadrak district early on Wednesday morning.
Country's largest airline has set up a centralised unit to minimise disruptions.