Bangladesh has a typical monsoon climate characterized by rain-bearing winds, moderately warm temperatures, and high humidity. In general maximum temperatures in the summer months, from April to September, range between 91°F and 96°F (33°C and 36°C). April is the warmest month in most parts. January is the coolest month in the winter season, which lasts from about November to March.
The conditions of the lowest atmospheric pressure occur in Bangladesh in June and July, the storm season. Winds are mostly from the north and northeast in winter, blowing at a rate of 1 to 2 miles per hour in northern and central areas and 2 to 4 miles per hour near the coast. During the period of northwesters (March to May), wind speeds may rise to 30or 40 miles per hour.
Bangladesh receives heavy rainfall; except for some parts in the west, it generally exceeds 60 inches (1,500 millimeters) annually. Large areas of the south, southeast, north, and northeast receive from 80 to 100 inches, and the northern and northwestern parts of Sylhet area receive from 150 to 200 inches. The maximum rainfall occurs during the monsoon period, from June to September or early October.
In the early summer (April to May) and late in the monsoon season (September to November), storms of very high intensity often occur; they may create winds with speeds of more than 100 miles per hour, piling up the waters of the Bay of Bengal to crests as high as 20 feet that crash with tremendous force onto the coastal areas and offshore islands, inundating them and causing heavy losses of life and property. Since the early 18th century, when records were first kept, more than 1,000,000 people have been killed in such storms, 815,000 of them in three storms occurring in 1737, 1876, and 1970. Severe storms also occurred in May 1985 and April 1991.
The conditions of the lowest atmospheric pressure occur in Bangladesh in June and July, the storm season. Winds are mostly from the north and northeast in winter, blowing at a rate of 1 to 2 miles per hour in northern and central areas and 2 to 4 miles per hour near the coast. During the period of northwesters (March to May), wind speeds may rise to 30or 40 miles per hour.
Bangladesh receives heavy rainfall; except for some parts in the west, it generally exceeds 60 inches (1,500 millimeters) annually. Large areas of the south, southeast, north, and northeast receive from 80 to 100 inches, and the northern and northwestern parts of Sylhet area receive from 150 to 200 inches. The maximum rainfall occurs during the monsoon period, from June to September or early October.
In the early summer (April to May) and late in the monsoon season (September to November), storms of very high intensity often occur; they may create winds with speeds of more than 100 miles per hour, piling up the waters of the Bay of Bengal to crests as high as 20 feet that crash with tremendous force onto the coastal areas and offshore islands, inundating them and causing heavy losses of life and property. Since the early 18th century, when records were first kept, more than 1,000,000 people have been killed in such storms, 815,000 of them in three storms occurring in 1737, 1876, and 1970. Severe storms also occurred in May 1985 and April 1991.