Multiple Heatwaves Forecast in April

Temperatures have surged sharply at the very onset of April, traditionally considered the hottest month in Bangladesh, with readings in some areas already approaching 40°C. Meteorologists have warned that the country is likely to experience several spells of heatwave activity throughout the month, alongside intermittent rainfall and thunderstorms that may temporarily disrupt the heat pattern.

According to the Bangladesh Meteorological Department, April may witness between two and four episodes of mild to moderate heatwaves, along with one or two severe heatwaves. These fluctuations are expected to significantly affect daily life, particularly in the western and south-western regions of the country, where temperatures are typically higher.

Heatwave classification

The intensity of heatwaves is defined based on temperature thresholds as follows:

On Saturday morning, meteorological observations indicated that a mild to moderate heatwave was affecting at least 18 districts across the Rajshahi and Khulna divisions. Additionally, several districts in Dhaka, Narayanganj, Manikganj, Faridpur, Gopalganj, Chandpur, Barishal, Patuakhali, and Rangamati were also experiencing similar conditions, resulting in widespread discomfort among residents.

The previous day, the highest temperature recorded in the country was 39.7°C in Chuadanga, which falls within the upper range of a moderate heatwave, signalling conditions close to severe heat intensity.

Meteorologists, however, suggest that the prolonged and extreme heatwave seen in 2024 is unlikely to repeat this year. In 2024, Bangladesh endured an exceptional 36 consecutive days of heatwave conditions, creating significant strain on public health, agriculture, and power supply. This year, intermittent rainfall is expected to break the continuity of heat spells.

Senior meteorologist Md Bazlur Rashid noted that rainfall is likely within the next couple of days, which may bring temporary relief by lowering temperatures. He emphasised that while heatwaves are a normal phenomenon in April, sustained and uninterrupted heat conditions like last year are not expected.

Another meteorologist, Md Tariful Newaz Kabir, observed that the south-western regions of the country are likely to remain comparatively hotter. However, the presence of scattered rainfall and thunderstorm activity is expected to prevent prolonged heatwave conditions.

Weather outlook for April

Forecasts suggest that April may also bring episodes of severe nor’westers (locally known as Kalbaishakhi), characterised by thunderstorms, strong winds, and occasional hailstorms. The country may experience around seven days of light to moderate rainfall accompanied by hail, and one to three days of thunderstorm activity with heavier downpours.

Meteorologists explain that hailstorms often occur when intense heat builds up rapidly, leading to high cloud formation. Once rainfall begins consistently, the likelihood of hail generally decreases.

March data indicates that average morning temperatures were 0.90°C above normal, reflecting an overall warming trend. The lowest temperature recorded during the month was 14.2°C in Rাজারhat, Kurigram, on 4 March, while the highest reached 37.8°C in Jashore on 27 March.

Rainfall activity was notably widespread during March, with precipitation recorded on 24 days. The highest single-day rainfall was 83 millimetres in Sylhet on 13 March. Overall, rainfall across the country was 31 per cent above normal, although divisions such as Khulna, Barishal, and Chattogram experienced below-average precipitation.

Looking ahead, meteorologists also indicated the possible formation of a low-pressure system towards the end of April. However, its intensification into a cyclone remains highly unlikely at this stage.

In summary, April is expected to be a month of climatic extremes for Bangladesh, characterised by alternating spells of intense heat, thunderstorms, and scattered rainfall—offering only intermittent relief from the prevailing heat stress.