Very high altitudes modify the climate in the cold, snow-covered northern mountains; temperatures on the Baluchistan plateau are somewhat higher. During summer, hot winds called Loo blow across the plains during the day.
The dry, hot weather is broken occasionally by dust storms and thunderstorms that temporarily lower the temperature. Estimation of regions where snow regularly falls monsoon and the Western Disturbance are the two main factors which alter the weather over Pakistan ; Continental air prevails for rest of the year.
Western Disturbances mostly occur during the winter months and cause light to moderate showers in southern parts of the country while moderate to heavy showers with heavy snowfall in the northern parts of the country. These westerly waves are robbed of most of the moisture by the time they reach Pakistan.
Fog occurs during winter and remains for weeks in upper Singh, central Khyber Pakhtunkhwa and Punjab. Southwest Monsoon occurs in summer from the month of June till September in almost whole Pakistan excluding western Baluchistan, Data, Chiral and Gil git–Batista.
Monsoon rains bring much awaited relief from the scorching summer heat. These monsoon rains are quite heavy by nature and can cause significant flooding, even severe flooding if they interact with westerly waves in the upper parts of the country.
Dust storms occur during summer months with peak in May and June, They are locally known as Gandhi. Heat waves occur during May and June, especially in southern Punjab, central Baluchistan and Singh.
Thunderstorms most commonly occur in northern Punjab, Khyber Pakhtunkhwa and Azad Kashmir. Pakistan has four seasons: a cool, dry winter from December through February; a hot, dry spring from March through May; the summer rainy season, or southwest monsoon period, from June through September; and the retreating monsoon period of October and November.
Half of the annual rainfall occurs in July and August, averaging about 255 millimeters in each of those two months. The remainder of the year has significantly less rain, amounting to about fifty millimeters per month.
Pakistan's largest city, Karachi, which is also the country's industrial center, is more humid than Islamabad but gets less rain. Only July and August average more than twenty-five millimeters of rain in the Karachi area; the remaining months are exceedingly dry.
The temperature is also more uniform in Karachi than in Islamabad, ranging from an average daily low of 13 °C during winter evenings to an average daily high of 34 °C on summer days. The weather extremes in Pakistan include high and low temperatures, heavy rainfall and flooding.
The highest temperature ever recorded in Pakistan is 53.7 °C (128.66 °F), in Turban, Baluchistan on 28 May 2017. The highest rainfall of 620 millimeters (24 in) was recorded in Islamabad during 24 hours on 24 July 2001.
Each year before the onset of monsoon that is 15 April to 15 July and also after its withdrawal that is 15 September to 15 December, there is always a distinct possibility of the cyclonic storm to develop in the north Arabian Sea. Cyclones form in the Arabian Sea often results in strong winds and heavy rainfall in Pakistan's coastal areas.
However, tornadoes mostly occur during spring season that is March and April usually when a Western Disturbance starts effecting the northern parts of the country. It is also speculated that cycles of tornado years may be correlated to the periods of reduced tropical cyclone activity.
Already, the massive droughts of 1998-2002 has stretched the coping abilities of the existing systems to the limit and it has barely been able to check the situation from becoming a catastrophe. According to the Economic Survey of Pakistan, the drought was one of the most significant factors responsible for the less than anticipated growth performance.
In 1992 flooding during Monsoon season killed 1,834 people across the country, in 1993 flooding during Monsoon rains killed 3,084 people, in 2003 Singh province was badly affected due to monsoon rains causing damages in billions, killed 178 people, while in 2007 Cyclone Remain submerged lower part of Baluchistan Province in seawater killing 380 people. Khyber Pakhtunkhwa and North eastern Punjab were badly affected during the monsoon rains when dams, rivers and lakes overflowed.
One month later, the data had been updated to reveal 1,781 deaths, 2,966 people with injuries, and more than 1.89 million homes destroyed. The flood affected more than 20 million people exceeding the combined total of individuals affected by the 2004 Indian Ocean tsunami, the 2005 Kashmir earthquake and the 2010 Haiti earthquake.
Singh is a fertile region and often called the “breadbasket” of the country; the damage and toll of the floods on the local agrarian economy is said to be extensive. At least 1.7 million acres of arable land has been inundated as a result of the flooding.
As a result of ongoing climate change, the climate of Pakistan has become increasingly volatile over the past several decades; this trend is expected to continue into the future. In addition to increased heat, drought and extreme weather conditions in some parts of the country, the melting of glaciers in the Himalayas threatens many of the most important rivers of Pakistan.
Pakistan contributes little to global greenhouse gas (GHG) emissions at about less than 1%, yet it is very vulnerable to the effects of climate change. Pakistan's lower technical and financial capacity to adapt to the adverse impacts of climate change worsen its vulnerability.
Food and water security, as well as large displacement of populations are major threats faced by the country. Pakistan's agriculture-dependent economy is especially susceptible to increasing irregularity and uncertainty over climatic conditions.
Like many other South Asian nations, Pakistan is faced by high risk due to climate change effects. CS1 main: archived copy as title (link) ^ Platform, International Recovery.