A cloudburst is an extreme amount of precipitation in a short period of time, sometimes accompanied by hail and thunder, which is capable of creating flood conditions. Cloudbursts can quickly dump large amounts of water, e.g. 25 mm of precipitation corresponds to 25,000 metric tons per square kilometre. However, cloudbursts are infrequent as they occur only via orographic lift or occasionally when a warm air parcel mixes with cooler air, resulting in sudden condensation. At times, a large amount of runoff from higher elevations is mistakenly conflated with a cloudburst. The term "cloudburst" arose from the notion that clouds were akin to water balloons and could burst, resulting in rapid precipitation. Though this idea has since been disproven, the term remains in use.
Karachi has an arid climate, albeit a moderate version of this climate. It is located on the coast bordering the Arabian Sea, and as a result, has a relatively mild climate.
The 2003 North Indian Ocean cyclone season was the last season that tropical cyclones were not publicly labeled by India Meteorological Department (IMD). Also was mostly focused in the Bay of Bengal, where six of the seven depressions developed. The remaining system was a tropical cyclone that developed in the Arabian Sea in November, which was also the only system that did not affect land. There were three cyclonic storms, which was below the average of 4–6. Only one storm formed before the start of the monsoon season in June, although it was also the most notable. On May 10, a depression formed in the central Bay of Bengal, and within a few days became a very severe cyclonic storm. After it stalled, it drew moisture from the southwest to produce severe flooding across Sri Lanka, killing 254 people and becoming the worst floods there since 1947. Damage on the island totaled $135 million (2003 USD). The storm eventually made landfall in Myanmar on May 19. It is possible that the storm contributed to a deadly heat wave in India due to shifting air currents.
Pakistan's climate is a continental type of climate, characterized by extreme variations in temperature, both seasonally and daily, because it is located on a great landmass north of the Tropic of Cancer.
The province of Sindh is situated in a subtropical region; it is hot in the summer and cold in winter. Temperatures frequently rise above 46 °C (115 °F) between May and August, and the minimum average temperature of 2 °C (36 °F) occurs during December and January. The annual rainfall averages about nearly 9 inches (230 mm), falling mainly during June and September. The southwesterly monsoon wind begins to blow in mid-February and continues until the end of September, whereas the cool northerly wind blows during the winter months from October to January.
Very Severe Cyclonic Storm Phet was a powerful tropical cyclone that made landfall on Oman, Western India, and Pakistan. The third named cyclone of the 2010 cyclone season, Phet developed in the Arabian Sea on May 31 to the west of India. With conducive environmental conditions, the storm intensified to reach peak sustained winds of 155 km/h (95 mph) on June 2, based on analysis by the India Meteorological Department (IMD). On the next day, Phet dropped heavy rainfall while moving across eastern Oman, with a peak of 603 mm (23.7 in) in Qurayyat. The rains flooded arid areas and collected into wadis – normally dry river beds. Thousands of homes were wrecked across Oman. There were 24 fatalities in the country, and damage was estimated at US$780 million.
The floods in Pakistan began in late July 2010, resulting from heavy monsoon rains in the Khyber Pakhtunkhwa, Sindh, Punjab and, Balochistan regions of Pakistan, which affected the Indus River basin. Approximately one-fifth of Pakistan's total land area was affected by floods, with the Khyber Pakhtunkhwa province facing the brunt of the damage and casualties. Nationwide, there were 1,985 deaths. According to Pakistani government data, the floods directly affected about 20 million people, mostly by destruction of property, livelihood and infrastructure.
Quetta, Pakistan features a continental semi-arid climate with a large variation between summer and winter temperatures. The highest temperature recorded in Quetta was 42 °C (108 °F) on 10 July 1998. The lowest temperature in Quetta is −18.3 °C (−0.9 °F) which was recorded on 8 January 1970.
The 2010 Gascoyne River flood was regarded as the most severe flood to take place along the Gascoyne River in Western Australia on record. Triggered by record-breaking rainfall, amounting to over 6,000 percent of the monthly mean, 313.6 mm (12.35 in) and 5 mm (0.20 in) respectively, in just four days, the floods caused widespread damage in the region. By 17 December, the river began to rise in response to the heavy rains, eventually exceeding its banks within two days. Water levels reached record values at three stations along the river, cresting at 15.53 m (51.0 ft) near Fishy Pool. Evacuation orders were issued for several towns affected by rising waters. The most substantial impact was felt in Carnarvon where entire homes were washed away. Following the disaster, emergency supplies and funds were distributed to affected residents to aid them in restoring their livelihoods. Though no people died in the event, an estimated two thousand head of cattle perished and damage was estimated at A$100 million.
The 2011 Balochistan floods started from the last week of February and continued until the first week of March. Balochistan province was already badly affected from last year's devastating floods as UNHCR claims that 166,000 flood victims are still homeless in the province with 240 people still living in camps.
The 2012 Pakistan floods began in early September 2012, resulting from heavy monsoon rains in Khyber Pakhtunkhwa, Upper Sindh, Southern Punjab and Balochistan regions of Pakistan.
In September 2014, the Kashmir region suffered disastrous floods across many of its districts caused by torrential rainfall. The Indian administered state of Jammu and Kashmir, as well as the Pakistani administered territories of Azad Kashmir, Gilgit-Baltistan and the province of Punjab were affected by these floods. By 24 September 2014, nearly 277 people in India and about 280 people in Pakistan had died due to the floods.
Widespread monsoon flooding occurred in the South Asian countries of Afghanistan, Bangladesh, India, Nepal and Pakistan from July through September 2017. More than 45 million people were affected by the floods, including 16 million children.
The 2020 Karachi floods were the worst flooding Karachi had seen in almost a century, and killed at least 41 people across Pakistan. The floods were caused by record monsoon rains, which were inadequately drained by poorly maintained drainage systems in the city. The resulting floods caused deaths and destruction of infrastructure and properties in the city.
From 14 June to October 2022, floods in Pakistan killed 1,739 people, and caused ₨ 3.2 trillion of damage and ₨ 3.3 trillion of economic losses. The immediate causes of the floods were heavier than usual monsoon rains and melting glaciers that followed a severe heat wave, both of which are linked to climate change.
