In a regular weather bulletin this morning, BMD said the southwest monsoon has advanced up to Barishal, Chattogram, Sylhet and Mymensingh divisions and eastern part of Dhaka division.

"Light to moderate rain or thundershowers with lightning flashes and temporary gusty wind is likely to occur at most places over Mymensingh, Dhaka, Khulna, Barishal, Chattogram and Sylhet divisions and at a few places over Rangpur and Rajshahi divisions with moderately heavy to very heavy falls at places over Khulna, Barishal, Chattogram and Sylhet divisions," the met office said in its 24-hour period forecast commencing 9:00am today.

The BMD also forecast rainfall activities in various places across the country in the next 96 hours after the end of the 24-hour period.

Meanwhile, in a warning message, BMD said under the influence of the well-marked low, gusty or squally weather may affect the maritime ports, North Bay and adjoining coastal areas of Bangladesh.

Maritime ports of Chattogram, Cox's Bazar, Mongla and Payra were advised to keep hoisted local cautionary signal No. 3.

Besides, all fishing boats and trawlers over North Bay were directed to remain close to the coast and proceed with caution till further notice.

During the 96-hour period, day and night temperature may fall slightly over the country in the first 24 hours, remain nearly unchanged in the next 48 hours and then rise slightly in the next 24 hours.

Meanwhile, the met office recorded the country's highest maximum temperature for yesterday at 38.4 degrees Celsius in Sylhet.

Yesterday, Dhaka's maximum temperature was 35.6 degrees Celsius.

Also, BMD said during 24 hours till 6:00am today, the country's highest 27mm rainfall was recorded in Ambagan of Chattogram.