Bangladesh is reeling under a mild heatwave spell, the weather department said on Thursday.

"Mild heat wave is sweeping through Rajshahi, Rangpur, Mymensingh and Khulna divisions and the districts of Gopalgonj and Manikgonj, and it may abate from some places," the Bangladesh Meteorological Department (BMD) said in a daily bulletin.

Besides, light to moderate rain or showers accompanied by temporary gusty wind is likely to occur at many places over Khulna and Barishal divisions; at a few places over Rajshahi, Dhaka and Chattogram divisions; and at one or two places over Rangpur, Mymensingh and Sylhet divisions with moderately heavy to heavy falls at places over southern Bangladesh, it added.

The rainfall activity may increase. Day and night temperatures may fall slightly over the country, as per the bulletin.

Read: Rains likely to quell heat in Bangladesh

The weather office recorded the highest rainfall of 35mm in Dimla of Rangpur division in 24 hours till 6am on Thursday.

The highest temperature was recorded at 37.5 degrees Celsius in Sayedpur of Rangpur division, while the lowest temperature was recorded at 26 degrees in Kutubdia of Chattogram division.

Meanwhile, a low pressure area has formed over the Northeast Bay and adjoining areas. It is likely to intensify, according to the weather department.

Monsoon is fairly active over Bangladesh and strong elsewhere over the North Bay, as per the bulletin.