Global Urban‐Rural Differences in Precipitation: Cities See More Light Rain But Milder Extremes
Earth's Future, 2026 · doi:10.1029/2025EF007370
Abstract
Ample evidence has shown that cities modulate regional hydrometeorology and hydroclimatology. Because different precipitation intensities have distinct hydrological and societal impacts, with light precipitation helping to alleviate urban heat and extreme precipitation often driving flood risks, it is important to understand whether and how urban effects vary with precipitation intensity. Based on global satellite‐based observations, we demonstrate that 70.1% of large cities experience increased light precipitation frequency, while 69.9% exhibit milder extreme precipitation magnitude than their rural counterparts. By further dividing the rural areas into upwind and downwind regions, we find that the frequency of light precipitation events is enhanced within cities, but such enhancements shift to the downwind rural areas as the precipitation intensity increases, notably for heavy precipitation (>20 mm) frequency and extreme precipitation indices. Moreover, we perform weather simulations with a real atmosphere and idealized land surface configuration, which reveal that urban surfaces modify the precipitation distribution with more areas of low precipitation intensity but a milder maximum precipitation intensity, consistent with satellite‐based observational results. The contrasting influence of cities on light and extreme precipitation suggests an underappreciated role of urbanization in improving local climate conditions.
Plain-language summary
More than half of the world's population lives in cities and cities are known to affect local weather and climate. However, it is unclear how cities influence precipitation of different intensities. This matters because light and heavy rain have very different impacts on society and the environment. Here we use global‐scale satellite‐based results to show that over 50% of the studied large cities receive more light rain but experience milder extreme rain compared to their nearby rural areas. We also find that this effect has strengthened from 2001 to 2020. By using numerical simulations, we further show that the rough surfaces of cities can change the distribution of rainfall, increasing the amount of light rain while limiting the maximum rainfall. These results highlight a previously underappreciated role of cities in shaping local climate conditions.
Key points
- More than half of cities experience enhanced light precipitation frequency but milder extreme precipitation magnitude than rural areas
- Light precipitation frequency is increased within cities, while the enhancement of extreme precipitation magnitude is in downwind areas
- This contrasting influence of cities suggests an underappreciated role of urbanization in improving local climate conditions
Read it
- Published version free at the publisher