Urban planning must factor in wind flow to combat city heat, experts warn

UPDATE - follow-up to Letting the wind flow freely is the secret to cooling our cities: Ground-level wind speeds in cities are dropping due to dense buildings and high-rise structures, which worsen heat stress and trap air pollution.

Urban Heat and Wind

Terrestrial stilling, or the global drop in wind speeds near the ground, has been happening worldwide since the 1980s. Amruthraj M.N., a consultant at the Indian Institute for Human Settlements in Bengaluru, points out that surface-level wind speeds drop significantly around 10 meters from the floor where pedestrians walk. Meteorologist Aaron Serre notes that dense buildings create turbulence and surface friction. Furthermore, replacing trees with asphalt and concrete cuts down evapotranspiration, which makes the urban heat island effect worse.

## Context

Urban heat islands form when cities replace natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat. Understanding how wind interacts with city architecture is crucial for designing cooler, more breathable urban spaces in the future.