UTCI (Universal Thermal Climate Index) is the gold standard for measuring perceived temperature. Unlike raw air temperature, UTCI accounts for humidity, wind speed, solar radiation, and radiant heat — everything that affects whether you're comfortable outdoors.
Why it matters
Raw temperature is misleading for comparing cities. A 30°C day in dry Lisbon feels very different from 30°C in humid Bangkok. UTCI captures that difference. It's the metric that answers "will I actually be comfortable outside?"
How we use it
We compute UTCI from ERA5 hourly reanalysis data (2015–2024) for 29,000+ cities. On the explore map, "Winter Feels-Like Temperature" shows the 25th percentile UTCI in the coldest month — how cold a cold day actually feels. "Summer Feels-Like Temperature" shows the 90th percentile in the hottest month — how hot a peak day gets.
What it doesn't capture
- UTCI measures outdoor thermal comfort. It doesn't account for air conditioning, indoor heating, or building quality.
- It's computed from satellite reanalysis, not local weather stations. Microclimates within a city (shaded streets vs open plazas) aren't captured.
See it in action
Every city page shows UTCI in the Climate Lab — month by month, with how it affects daily comfort. The explore map lets you filter cities by winter and summer feels-like temperature.