As the monsoon leaves by the first half of this month, the season of cyclone begins. As a fallout, there may be at least one or two low pressure areas in the Bay of Bengal, says a long-range forecast by the meteorological department. The forecast yesterday  noted that the south-west monsoon, which ushers in the rainy season in Bangladesh, may wind up finally by the first half of the month, after causing more than normal average rainfall in September in the country. The met office said the monsoon has already started packing up, which is why there has been a lack of rainfall since last week, resulting in an unusually hot and humid weather. The rainfall in October is likely to be a little less than average. The rainfall pattern in September varied from region to region. There was 30 per cent more than average precipitation in the south-eastern Chittagong division, against 40 per cent less than normal rainfall in the north-western Rajshahi division. There were two low pressure areas in the Bay of Bengal in September that engineered  heavy to very heavy rainfall  in the country in three spells from the beginning to the end of the month -- September 1-4, 13-15 and 19-24.