The minimum and maximum temperatures in the national capital will hover around 28 degrees Celsius and 39 degrees Celsius while in the financial capital it will be 25 degrees Celsius and 32 degrees Celsius.
On Tuesday, the weatherman had said rains are likely to elude Delhi for the next three to four days.
Thunderstorm accompanied by lightning is very likely at isolated places in Gangetic West Bengal and Odisha, according to the weather forecast.
The IMD said heavy to very heavy rainfall is very likely at isolated places in Konkan and Goa, Sub-Himalayan West Bengal, Sikkim, Assam and Meghalaya.
Heavy rainfall is expected at isolated places in coastal Karnataka, Bihar, Arunachal Pradesh and Nagaland, Manipur, Mizoram and Tripura, it said.
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Rough sea conditions are likely to prevail in south-western and adjoining west-central Arabian Sea. The weather office has advised fishermen not to venture into these areas.
Meanwhile, monsoon may take a week longer to reach the national capital. Normally, the wind system reaches the city by June 29.
(With inputs from PTI)