The district of Dinajpur lies north of the Tropic of Cancer, and its climate approximates more to that of Bihar (India) than to that of the eastern districts of Bangladesh. The winter season may be said to set in early in November and to continue until the end of February. Although in a normal year the days begin to be hot towards the later part of February, the nights begin to be hot towards the latter part of February; the nights remain cool until well into April. The summer season begins with strong westerly winds around the beginning of March and continues up to early June. The west is the prevailing wind till about the middle of April. By April the nor’wester thunder-storms begin to occur which bring heavy showers fairly frequently until May. The climate during the summer is by no means unbearable. With the break of the monsoon, which generally occurs around the beginning of Jone, the rainy season commences and continues till the end of September or beginning of October. The heaviest rain usually falls in June, July, August and September. With the setting in of the rains the climate changes and becomes excessively moist. The higher relative humidity from August to the middle of October makes the weather depressing. From the middle of October , the nights become appreciably cooler, though the days remain hot for some time longer. During the winter season, days are bright and sunny and the atmosphere crisp and clear. Dinajpur is the coldest district in Bangladesh and so sometimes in January fires are necessary. Little rainfalls during the winter with the exception of some light showers towards the end of December, and a thunderstorm or two in February. In December easterly and northerly winds are common.