ABSTRACT
The climate of Bangladesh is characterised by high temperatures, heavy rainfall, often excessive humidity and fairly marked seasonal variations. There are three main sources of rainfall in Bangladesh; the western depressions of winter, the early summer thunderstroms known as the Nor'-westers (North-Westerlies), and the summer rains from the S. W. Trades known as the monsoons. The main rainy period begins with the coming of the moistureladen south-west-trades which are drawn to the Indian Sub-Continent by the intense heat and consequent low pressure over the Punjab and Upper Ganges Valley and the filling up of the 'equatorial' lows by air masses from these very hot areas. Typhoons are Tropical Revolving Storms, not uncommon within the Inter-tropical Belt. Typhoons are called 'Cyclones' in English, when they occur in the Indian Ocean area. They are however called Tufan in Bengali, from the Chinese Tai-fun.
