UTCI by season and time of day
C4B calculates the Universal Thermal Climate Index (UTCI) for the site, including a solar correction of the mean radiant temperature, and shows it as heatmaps across seasons and hours in seven thermal stress bands. It is available on the Free plan with weather-station data.
Outdoor comfort strategies
Projects on a paid plan compare comfort under four exposure cases, from full sun and wind to shade and wind shelter, so you can see which intervention extends the comfortable hours of a terrace, square or courtyard. Directional outdoor comfort strategies add comfort by wind direction and windbreak guidance.
See your site's climate before design begins
Pin any location and get climate, comfort and preliminary energy insight your whole team can read. Start with a 7-day free trial, or book a 30-minute demo.
Frequently asked questions
What is UTCI?
The Universal Thermal Climate Index is an equivalent temperature that expresses how the combination of air temperature, humidity, wind and radiation feels to the human body outdoors. It is grouped into thermal stress categories from extreme cold stress to extreme heat stress.
Why does outdoor comfort matter for building design?
Entrances, terraces, courtyards and public spaces are only used when they are comfortable. Knowing when and why they are not helps decide shading, planting, wind protection and orientation early.
Can I see how outdoor comfort will change in the future?
Yes. Projects can overlay future climate scenarios on the UTCI analysis.
Learn the concepts
How to read a wind rose
Petals, frequency rings, speed bands and calms explained, with the checks and design uses that matter on a building project.
UTCI (Universal Thermal Climate Index)
What UTCI measures, its four inputs, the ten stress categories with their thresholds, its limits and how to use it in outdoor design.
Related features
Wind rose
Annual and daily wind roses showing wind direction and speed, by season and time of day.
Future climate scenarios
Future weather files for any year up to 2100 under five SSP scenarios, overlaid on the project's analyses.
Sun path diagram
Sun path diagrams in 2D, 3D and globe views, together with monthly daytime cloud cover.