Hong Kong Weather Flipping From Wet to Dry Extremes As Climate Change Throws Water Cycle ‘Out of Balance’

Hong Kong, Cairo, Madrid, Riyadh, and Jeddah topped the list of cities facing a flip from extremely wet to extremely dry conditions, a new report commissioned by non-profit WaterAid has found.

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Climate change is making once-wet cities like Hong Kong exponentially drier, according to new research on the climate change-driven shifts of weather patterns in urban areas around the world.

The academic study, commissioned by non-profit WaterAid, looked at the world’s top 100 most-populated cities and 12 other cities. It concluded that 44% of urban centers worldwide were getting drier. Hong Kong, along with Egypt’s capital Cairo, Spain’s capital Madrid, and the Saudi Arabian cities of Riyadh and Jeddah, topped the list of cities facing increasing dry extremes.

Researchers said Hong Kong “is not only drying but also experiencing a flip in climate hazards [from extreme wet] to more extreme dry conditions,” a phenomenon they identified in 7% of all cities analyzed.

The shift is due to increased moisture evaporation triggered by warmer temperatures, the report said. The world has just recorded its hottest year in history and the first one with temperatures rising to more than 1.5C above pre-industrial levels, wrapping up a decade of unprecedented heat globally fuelled by human activities.

The shift in weather patterns also sees cities such as Sri Lanka’s Colombo, Mumbai in India and Malaysia’s capital Kuala Lumpur flip from dry to wet. According to the report’s findings, which are based on the analysis of four decades of wetting and drying trends, 52% of the world’s most populated cities are getting wetter.

13% of these – including several Indian and Pakistani cities, as well as Colombia’s capital Bogotá and Ho Chi Minh City in Vietnam – are experiencing a flip from extreme dry to extremely wet.

South and Southeast Asia in particular emerged as a hotspot with a strong wetting trend, vulnerable to increased wet and extreme wet climate that increases the likelihood of extreme flooding, putting millions of livelihoods at risk. A United Nations report last year found that Asia was the hardest-hit continent by climate change in 2023, with floods and storms comprising over 80% of all weather hazards that year.

15% of big urban areas are experiencing an intensification of both droughts and floods, a phenomenon the report calls “climate whiplash.” Weather-related disasters like these have increased by a factor of five over the past 50 years, according to the World Meteorological Organization.

Record-Breaking Year

2024 was Hong Kong’s hottest year since at least 1884, when authorities first began tracking temperature trends.

The city saw a total of 35 record-breaking high temperature events. These included the highest absolute maximum temperature on record for March at 31.5C, the warmest April on record with temperatures significantly above normal, the warmest first half-year on record, and the highest number of hot nights for August.

These high temperatures were attributed to various factors like warmer sea surface temperatures, stronger southerly flows, and weaker monsoon patterns, the city’s Observatory said in January.

The total annual rainfall in 2024 was 2,309.7 millimetres (mm), some 5% below the 1991-2020 normal of 2,431.2 millimetres, according to the Observatory.

The first two months of 2025 were also drier than usual in the city. 4.2mm of rainfall were recorded in January, only about 13% of the normal of 33.2mm for the month, while the total rainfall recorded in February was 26.1mm, about 33% below the normal of 38.9 millimetres.

The trend is set to continue this spring, which the Observatory forecasts to be warmer and drier than usual.

Featured image: Kyle Lam/hongkongfp.com