The country’s maritime ports have been advised to hoist the local cautionary signal 3 as deep convection is taking place over the North Bay, said the weather department on Thursday.

Squally weather is likely to affect the maritime ports, the North Bay, and the adjoining coastal areas of Bangladesh, said the Met office.

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And so, maritime ports in Chattogram, Cox’s Bazar, Mongla, and Payra have been advised to hoist local cautionary signal 3.

"All fishing boats and trawlers in the North Bay have been advised to remain close to the coast and proceed with caution until further notice," it reads.

“Rain or thundershowers accompanied by temporary gusty or squally wind are likely to occur at many places over Chattogram and Barishal divisions, at a few places over Dhaka and Khulna divisions, and at one or two places over Rangpur, Rajshahi, Mymensingh, and Sylhet divisions, with moderately heavy to heavy falls at places over Chattogram and Barishal,” the Met Office said.

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A severe heatwave is sweeping over the districts of Rajshahi, Pabna, Noagaon, Dinajpur, Jashore and Chuadanga.

Dhaka and Mymensingh divisions, parts of Rangpur, Rajshahi and Khulna divisions, and the district of Sylhet are witnessing a mild to moderate heatwave, and it may abate in some places.

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Daytime temperatures may fall by 1-3 degree C and nighttime temperatures may fall slightly across the country. A trough of westerly low lies over India's West Bengal and adjoining area.