Monsoon may arrive a week late: Met office

The Bangladesh Meteorological Department (BMD) has forecast below-normal rainfall and higher-than-usual temperatures at the beginning of this year's monsoon season.

Although the month of June began today, the country may have to wait another week for the monsoon to officially set in, according to the BMD’s long-range weather forecast bulletin released this afternoon.

In its one-month outlook, the department said the monsoon is expected to arrive across the entire country during the first half of June.

According to the forecast, Bangladesh as a whole experienced normal rainfall in May. The normal average rainfall for May in Bangladesh is 269 mm. The country recorded 289 mm of rainfall during the month, 7.4 percent higher than normal. The BMD, however, classified the increase as normal rainfall.

However, Rangpur Division recorded 513 mm of rainfall -- 98.7 percent higher than its normal level of 268 mm.

In contrast, Chattogram, Khulna and Barishal divisions received below-normal rainfall, while the remaining divisions recorded above-normal precipitation.

The forecast also said that two to three mild heatwaves, with temperatures ranging from 36°C to 37.9°C, to moderate heatwaves, with temperatures between 38°C and 39.9°C, may sweep across isolated parts of the country during June.

Asked about the reasons behind the forecast of lower rainfall and higher temperatures, BMD Meteorologist Md Bazlur Rashid told The Daily Star, “Normally, when there is less rainfall, day and night temperatures will naturally be higher. However, from June, Bangladesh has entered the sphere of influence of El Niño. Along with that, there are other factors involved, such as the Indian Ocean Dipole (IOD) and a few other reasons.”

Speaking about the possible impact on Bangladesh if a Super El Niño or a stronger El Niño develops, he said, “Even if El Niño becomes very strong, its impact on Bangladesh will remain weak.”