Big cities receive more drizzle than their surrounding areas

"Houston receives an average of 12cm more rain a year than its surrounding rural hinterland. And Houston isn't alone. As well as being urban heat islands, rainfall data shows that the world's largest cities tend also to be urban wet islands. Now new research shows much of this extra rain falls as light drizzle and that the urban wet island effect has strengthened over the last two decades."

"Their results, published in Earth's Future, show that more than two-thirds of large cities receive more light rain than the rural surrounding area. While this regular drizzle might not be appreciated by a city's inhabitants, it helps to replenish surface water. But the effect wasn't even. They found that while large cities in North America, eastern Asia and western Europe all tended to receive more drizzle, large tropical cities in south and south-east Asia did the opposite and exacerbated extreme rainfall events."

Major cities function as urban wet islands, receiving significantly more precipitation than their rural surroundings due to altered air flow, heat absorption, and urban infrastructure. Research analyzing satellite weather data reveals that more than two-thirds of large cities receive increased light drizzle compared to rural areas. This regular precipitation helps replenish surface water resources. However, the effect varies geographically. Cities in North America, eastern Asia, and western Europe experience more frequent light rain, while large tropical cities in south and south-east Asia show opposite patterns, intensifying extreme rainfall events instead.

Read at www.theguardian.com