Moitrayee Das
The rainy season stretches from July to the end of September in Indian sub-continent. During this period, the South-West Monsoons pick up moisture from the Bay of Bengal and blow over the state of West Bengal. Most of the annual average rainfall of 175 cm about 125 cm occurs during this period. Heavy rainfall of above 250 cm is observed in the Darjeeling, erstwhile Jalpaiguri (from 2014 the district has been divided into two administrative unit viz Jalpaiguri and Alipurduar) and Cooch Behar district. Among these districts, Jalpaiguri district is the only district of West Bengal, situated in the foothill region of eastern Himalaya. The total areal extent of this district is 6227 km2. Taking consideration about the areal extent IMD (Indian Meteorological Development) has been established total eight metrological station within this district. Theissen Polygon has been applied to manage these eight station to find out the exact rainfall pattern in this spatial extend. Present paper is to represent the variation of monsoon rainfall in respect of depth, volume and probability in same physiographic condition within large areal extend.