Marked meteorological contrasts are currently defining atmospheric conditions across Bangladesh, characterized by heavy precipitation drenching segments of the eastern and coastal corridors alongside persistent mild heat waves gripping multiple western and central regions, per findings released by the Bangladesh Meteorological Department (BMD).

The agency attributed this thermal and precipitation dichotomy to a weakened monsoon footprint over mainland Bangladesh coupled with moderate activity over the northern Bay of Bengal, alongside a monsoon trough extending across the middle of the country.

Precipitation tracking over the 24-hour window ending at 6 am on Thursday showed peak accumulations concentrated in eastern and coastal zones, led by Rangamati at 65 millimetres, Sitakunda at 54 millimetres, Kutubdia at 34 millimetres, Chandpur at 31 millimetres, Feni at 28 millimetres and Madaripur at 27 millimetres.

Concurrently, elevated thermal readings persisted across western, northwestern, and central zones, topped by Jashore at a maximum of 36.4 degrees Celsius and Koyra at 36.2 degrees Celsius while Dhaka, Faridpur, Bogura, and Rangpur each logged 36.0 degrees Celsius.

A mild thermal wave currently affects Dhaka, Faridpur, Rangpur, Jashore and Khulna districts, though anticipated to dissipate soon.

Looking ahead for the 24 hours commencing at 9 am on this day, the BMD anticipates light-to-moderate rain or thundershowers accompanied by brief gusty winds across many locations in Rangpur, Dhaka, Mymensingh, and Sylhet divisions, and at isolated spots across Rajshahi, Khulna, Barishal, and Chattogram divisions.

Precipitation prospects for September 18 indicate light thundershowers at one or two places across all eight administrative divisions, whereas September 19 expects widespread rainfall across Chattogram, Barishal, and Sylhet divisions alongside scattered occurrences in Rangpur, Rajshahi, Mymensingh, Dhaka and Khulna divisions.

Forecast models for September 20 project isolated showers across Rangpur, Rajshahi, and Khulna divisions with spotty activity in Mymensingh, Dhaka, Barishal, Chattogram, and Sylhet, followed by widespread scattered rains across all divisions on September 21.

Thermal trajectories are projected to dip marginally on Thursday, hold steady during daytime and tick up slightly overnight on September 18, edge upward across both day and night on September 19, keep daytime values steady with cooler nights on September 20, and flatten out universally on September 21.

This meteorological divergence precedes potential maritime system shifts over the Bay of Bengal, with Md. Tariful Newaz Kabir, Deputy Director of the BMD Storm Warning Center, noting, "A low pressure area is likely to form over the North Andaman Sea and adjoining Eastcentral Bay by 19th September, 2026 and it may intensify."

Counterbalancing the high thermal readings, Srimangal registered the nation's lowest minimum temperature at 22.5 degrees Celsius over the same 24-hour tracking period.

In the capital, morning relative humidity stood at 86 percent at 6 am, accompanied by southern or southeastern airflow moving at speeds of 10 to 15 kilometres per hour.