CLARA environmental intelligence.

High-resolution, physics-based environmental digital twins
for urban resilience.

Air quality
Wind
Temperature
NoiseSoon
Past, present and forecast
1 m spatial resolution
Live in Brussels since June 2025
How it works

From a 3D city model to hyper-local data.

3D city model

Buildings, terrain, streets

Live data ingestion

Earth observation · Ground sensors · Weather forecasts

CFD + AI urban physics simulator

Physics + ML · past, present and forecast

Wind

Air

Temperature

NoiseSoon

Three ways to deliver the digital twin

One engine. Three channels.

CLARA data flows where it's needed: to data platforms, to administrations and to citizens.

CLARA API

Stream high-resolution environmental data straight into smart-city, real-estate, news, HORECA and other data platforms.

  • Real-time + forecast endpoints
  • Point, area & raster queries
  • Enterprise SLA & secure auth
Available now

CLARA-web

A web platform built for local administrations.

  • City-wide environmental dashboards
  • Historical & forecast layers
  • Operational decision support

First application

BrusAir was developed for the Smart City program of the City of Brussels and has been live since June 2025, providing high-resolution air quality data to city administrators and citizens.

brusair.be
Release · September 2026

CLARA-app

A free service for citizens: live location-based alerts, hourly forecasts, statistics.

  • Per-location alerts and statistics
  • Real-time & forecast maps
  • Interactive 3D explore-map
Public release · June 2026 · Free
Who uses CLARA

Use Cases

// one call per listing

GET api.clara.city/v1/historical/stats
    ?address=Chaussée de Waterloo 182, Ixelles

{
  "air":     { "no2": "...", "pm25": "..." },
  "wind":    { "comfort": "...", "gusts": "..." },
  "thermal": { "utci": "...", "heat": "..." }
}

// air quality, wind and heat
// at the address, from years of data

Smarter real estate CLARA API

The Real-Estate Portal

Property portals plug CLARA into their pages through the API. Each listing gets an environmental report: air quality, wind and temperature at the address, built on years of hyper-local data.

The agent said it was a great location. The report showed the balcony sits in a pollution hotspot. We kept looking.

clara.city
CLARA-web thermal comfort view
Climate resilience CLARA-web

The City

During a heat wave, the city's resilience team uses CLARA-web to find the streets and squares that overheat, compare them with previous summers, and test where trees or shading would help the most.

We see the thermal hotspots street by street, and we can show why we intervene on one square and not on another.

clara.city
CLARA-web air quality view
Air quality policy CLARA-web

The Mobility Department

The mobility department is considering a school street. In CLARA-web they see how traffic pollution gathers around the school at drop-off time, and compare air quality before and after the change, street by street.

We could show parents the difference the school street makes, with data from their own street, not a city average.

This video was produced with the assistance of AI tools.

Safe Route CLARA-app

The Cyclist

Everyday Sara commutes from home to work using her bike. Weather conditions can be harsh in Brussels and wind conditions dangerous.

CLARA shows me exactly which streets are shielded from the wind. I can ride home safely!

This video was produced with the assistance of AI tools.

Operational efficiency & safety CLARA-app

The Restaurant Manager

Adam uses CLARA to optimize staffing levels and stay ahead of weather risks, ensuring a safe and comfortable experience on the terrace.

If the app predicts high wind on our street at 19:00, I cancel the extra waiters. I also get alerts to close the parasols before a gust hits. It saves me money and protects my clients.

This video was produced with the assistance of AI tools.

Healthy living CLARA-app

The School

In her classroom, everyday Olivia used to guess when to open the windows. With CLARA, she can see exactly when the air outside is clean.

I ventilate at the right moment and keep my pupils safe from traffic pollution.

What CLARA is

CLARA urban environmental digital twins.

Starting from a 3D model of a city, CLARA ingests live data from Earth observation, ground sensors and weather forecasting services into its urban physics simulator based on Computational Fluid Dynamics, accelerated with machine learning, to deliver fast and accurate digital twins of the urban environment: wind, air quality, temperature and, soon, noise.

Cities need this level of detail because conditions change from one street to the next. A building corner turns a breeze into dangerous gusts, a street canyon holds traffic pollution while the avenue nearby stays clean, and a paved square can run several degrees hotter than a shaded courtyard around the corner. Data averaged over a whole neighbourhood misses all of this, and with it the answers people and administrations actually need: which route, which square, which building.

Standard tools stop well before the street. Regional air quality models work at resolutions of a hundred meters to several kilometers1, the weather models behind consumer wind and temperature forecasts at 1 kilometer or more2, satellite observations at a hundred meters to several kilometers3, and official noise maps are static documents, redrawn every few years4. CLARA resolves the city at 1 meter, street by street, building by building, across all of its layers.

Accuracy is the other difference. Most alternative services spread sensor readings over the map with simplified statistical models, or rely on data alone. CLARA works the other way around: its engine solves the fundamental laws of physics (wind motion, pollutant dispersion, heat transfer) on hundreds of millions of computational cells, and uses sensor and satellite data to estimate what the physics alone cannot know. Being physics based makes CLARA accurate in places where no sensor exists, and predictive in conditions that have never been measured, including scenarios that have not happened yet.

1. For example, the Copernicus CAMS European air quality ensemble runs at about 10 km (atmosphere.copernicus.eu), and interpolation-based national services such as RIO in Belgium at 4 km (Janssen et al. 2008, Atmospheric Environment).

2. For example, the global ECMWF IFS-HRES model runs at about 9 km (ecmwf.int), and high-resolution national models such as AROME at 1.3 km (Météo-France).

3. For example, Sentinel-5P TROPOMI resolves NO2 at 5.5 x 3.5 km (Veefkind et al. 2012, Remote Sensing of Environment), and Landsat thermal imagery resolves surface temperature at about 100 m (NASA Landsat).

4. Strategic noise maps under EU Directive 2002/49/EC are reviewed every five years (Environmental Noise Directive).

For municipalities

Bring CLARA to your city.

We generate the digital twin of your territory, you get the dashboards: heat, wind, air quality and soon noise, at 1-meter resolution. The City of Brussels already uses this technology through BrusAir. We can prepare a demo on your own municipality, with no commitment.

The citizen app

A closer look at the CLARA-app.

Currently in testing, free for everyone in June 2026.

CLARA App Screenshot 1
CLARA App Screenshot 2
CLARA App Screenshot 3
CLARA App Screenshot 4
CLARA App Screenshot 5
CLARA App Screenshot 6
CLARA App Screenshot 7

Swipe to explore

Scientific Transparency

Science and validation

CLARA is built on peer-reviewed research by our team and its academic partners, and its predictions are checked against field measurements and reference solutions. Both the validation report and the publications behind the engine are public.

Validation Report Preview

Validation CLARA

Release 2026

92%

Average
Accuracy

Roadmap

What comes next.

June 2026

CLARA-app · public release

Currently in testing. Releasing to the general public, entirely free of charge, in June 2026.

Now in open testing
September 2026

CLARA-web · launch

Web-based platform for local administrations. City-scale dashboards, decision support and analytics.

Autumn 2026

Noise maps

Noise joins wind, air quality and temperature: on the API in September, in the CLARA-app in October.

2027 and beyond

More cities

From 3 covered cities at the end of 2026 to 9 by the end of 2027 and 21 by the end of 2028.

What's next

Beyond the digital twin.

Capabilities currently in development.

Under development

UMAT

Urban Microclimate Adaptation Tool

Test urban adaptation strategies (greening, materials, shading) and assess renewable energy potential.

Under development

CURA

City Urban Resilience Assistant

An AI layer that interprets CLARA's high-resolution environmental data and suggests urban adaptation strategies.

Under development

CLARA Shield

Disaster and dual-use applications

High-resolution environmental prediction for emergency response, civil protection and dual-use scenarios.

Try CLARA, today.

Contact us

Or write to us directly at [email protected]

Get CLARA-app. It's free.

Get it on Google Play

Open Beta

Download on the App Store

Open Beta via TestFlight