The monsoon rains currently gripping the country will peak next month, met office said Jul 23. "We expect heavy showers during the month of August when monsoon rains will be at their peak," a met office spokesman told APP.
The average monsoon rainfall for the country between the months of July and September is 137.5 millimetres, which is based on precipitation data for the last 30 years.
Although geographically Pakistan's climate is classified as arid to semi-arid, yet parts of Punjab, NWFP and northern areas are most affected by the monsoon currents originating in Bay of Bengal. They can some time also stretch to parts of Sindh and Balochistan and coastal areas, but the amount of rain there is negligible.
Since Pakistan lies at the fringes of monsoon rains, therefore by the time the moisture-laden clouds reach Pakistan, they have already dumped most of the rain in Bangladesh and India.
Himalayan ranges are the main hurdle in their way from causing torrential rains in Pakistan. In Islamabad, the average rainfall for the month of July and August is 267 millimeters and 330 mm respectively.
Weather and environment experts say that the phenomenon of global warming has pushed back the monsoon rains in Pakistan. This year they started towards the end of June instead of first or second week of July.
Since the first heavy downpour on June 8, the twin cities of Rawalpindi and Islamabad have so far received slightly over 207 mm of rain.
"For the next four to five days we are expecting at least 100 mm of rain as a strong weather system is currently lying over Pakistan," met office said.
It has been noted over the last few years that it usually rains at night or in late evening. A weather expert explained that moist monsoon currents need lower temperatures to cool down and produce rain. "Since the day temperatures are fairly warm, therefore we usually have rains during the evenings or at nights," he added. He, however, said that if the winds from west or north, which are cooler, start to blow they can cause rain even during the day.