A severe heatwave has been sweeping across the major part of the country for the past six days of ongoing June. There was no previous record in the past 44 years of heatwave sweeping across the country for six days at a stretch in June. The country experienced such severe heatwave for five days at a stretch in June in 1979, said a source from the Bangladesh Meteorological Department (BMD).
According to the BMD, the new spell of heatwave started in the country on 28 May and has been continuing. That means the heatwave has been sweeping across the country for 10 days at a stretch. In some parts the heatwave is mild, in some parts it is moderate while in some parts the heatwave became severe. The heatwave is likely to continue for another four days.
As per the BMD, if the temperature remains between 36 and 37.9 Degrees Celsius, it is called mild heatwave; if it remains between 38 and 39.9 Degrees Celsius, it is called moderate heatwave; and, when the temperature remains between 40 and 41.9 Degrees Celsius, it is called severe heatwave. When the temperature crosses 42 Degrees Celsius, is identified as very severe heatwave.
Speaking to Prothom Alo, meteorologist Md Omar Faruq said on Tuesday, “Severe heatwave swept across the country from 1-5 June in 1979. The temperature crossed 40 Degrees Celsius every day. The highest temperature in that year was recorded at 43.5 Degrees Celsius in Jashore on 3 June.”
Omar Faruq also said the country experienced severe heatwave for three days at a stretch in June, 2005. The temperature did not cross 40 Degrees Celsius even for a day in June in 2021 and 2022.
The Bangladesh Meteorological Department said this or that part of the country experienced severe heatwave in the first six days of ongoing June. The severe heatwave swept over Rangpur, Dinajpur and Syedpur on 1 June; on 2 June the severe heatwave swept across Rajshahi, Dinajpur, Nilphamari, Jashore and Chuadanga; on 3 June, Rajshahi, Dinajpur and Nilphamari experienced the severe heatwave; on 4 June, severe heatwave swept across Dinajpur and Nilphamari; on 5 June, this was the temperature in Rajshahi and Pabna while on 6 June, the severe heatwave swept across Rajshahi, Dinajpur and Syedpur.
April and May are known as hottest months in the country. The amount of rainfall was less than normal in both the months this year. The BMD issues an extended forecast for one month at the beginning of each month. The extended forecast for June was issued on 2 June, which said the amount of rainfall was 44 per cent less than normal in May. The trend would continue in June too.
Severe cyclone Mocha crossed Teknaf coast of Bangladesh on 14 May. Though rainfall was recorded in Cox’s Bazar, Chattogram, and the neighbouring areas, there was almost no rainfall in other parts of the country. However, it rained in various parts of the country after two days of the onslaught of Mocha. The rainfall declined significantly at the last week of May and the heatwave started from 28 May.
Meteorologists said delay in arrival of monsoon is the reason of low rainfall, and the heatwave has been sweeping across the country due to increased temperature. The data of past 30-year says the monsoon generally arrives in the country through Teknaf in Cox’s Bazar on 31 May. Then it gradually spreads to Cox’s Bazar, Chattogram and other parts of the country. But this time the monsoon is yet to arrive. Last year the monsoon arrived on 23 June and in the previous year the date was 14 June.
Speaking to Prothom Alo, meteorologist Abul Kalam Mullick on Tuesday said, “The temperature in the country is rising during the time of pre-monsoon period (March – May).”
Highlighting the data from 1988 to 2019, he said the frequency of mild, moderate and severe heatwave has increased. Temperature is mainly rising in some parts of southwestern and northwestern districts of the country.
In the weather forecast for 24 hours, the BMD on Tuesday evening said severe heatwave has been sweeping over Jashore, Rajshahi, Dinajpur and Syedpur distircts. Mild to moderate heatwave has been sweeping over Chattogram, Cumilla, Chandpur, Noakhali, Feni and Bandarban districts and in Dhaka, Mymensingh, Khulna, Barisal, Sylhet divisions, and in the remaining parts of Rangpur and Rajshahi divisions. This heatwave is likely to continue.
The day-time temperature might decrease slightly in Barishal and Chattogram divisions while the temperature will remain unchanged in other parts of the country.