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Mannheim in the urban climate model at 14:00, seen obliquely from the south: the hottest air stands as a red volume above the densely built-up districts, streets and railway yards; the Rhine, the Neckar, parks and fields remain clear because their air is cooler. The buildings stand within it as grey bodies.
Air temperature as a 3D volume · 14:00 30.5 °C ≥ 35 °C FITNAH-3D · 0–60 m above ground, only air from 30.5 °C · Mannheim

The Urban Digital Climate Twin

The Urban Digital Climate Twin – in German Urbaner Digitaler Klimazwilling, abbreviated UDK – combines basic geodata and other local environmental data with detailed, validated modelling and real-time measurements to form a digital replica of a city's weather. It is updated every hour, all year round. This makes visible how temperature extremes, soil moisture, cold air and strong winds are distributed across the city and how they change over time. A foundation for sound, climate-sensitive decisions in cities.

Request a demo View the modules

A cooperation of

  • GEO-NET – website (opens in a new window)
  • planGIS – website (opens in a new window)

Supported by

  • Smart City Mannheim – website (opens in a new window)

What is the UDK?

of expertise in environmental meteorology
25+ years
training data points for AI-based methods
1 bn+
Validated models: FITNAH-3D · ASMUS_green · PALM-4U – checked against measurements
Scientifically sound
Experienced meteorologists, spatial planners and geographers with hands-on experience in municipal processes
Personally available
Scientific publications and open-source code
Transparent

For people who turn urban climate into decisions.

The UDK creates a shared local data basis – for digital strategies, concrete planning, municipal operations and public dialogue.

Smart city and digitalisation units
Integrates urban climate data into municipal digital strategies, smart city projects and digital twins.
Architects, urban planners and expert consultants
Compares options and assesses the effect of designs and measures in space and time.
Specialist departments and municipal utilities
Assesses heat, cold air and strong winds for urban development, climate adaptation, green spaces, heat planning and operations.
Politics and civil society
Makes climate risks and planned measures understandable – as a basis for transparent decision-making and local dialogue.
Social institutions and operators of critical infrastructure
Identifies local exposure, prioritises precautions and strengthens the protection of vulnerable people and essential services.
Local businesses
Assesses heat and weather risks for office locations, supply chains and production processes – and plans targeted operational precautions.

The six modules of the Urban Digital Climate Twin

From heat, cold air and strong winds through planning scenarios to measurements, real-time maps and forecasts: the modules illuminate different facets of the urban climate and together create a sound basis for municipal decisions.

Mannheim in the urban climate model, seen obliquely above building blocks and halls: the air temperature is coloured as a surface from blue (cooler) to red (warmer); it is shown successively at heights from 3 m to 20 m above ground.
Air temperature at 3 m to 20 m above ground · 04:00 FITNAH-3D · Mannheim
Mannheim at 04:00 at night in the urban climate model, seen from above at an angle: particles drift with the cold-air flow above buildings and open spaces; their colour shows the wind speed.
Wind speed m/s
  • 0 to 0.4 m/s
  • 0.4 to 0.8 m/s
  • 0.8 to 1.1 m/s
  • 1.1 to 1.5 m/s
  • 1.5 to 1.9 m/s
  • 1.9 to 2.3 m/s
  • 2.3 to 2.6 m/s
  • 2.6 to 3.0 m/s
Cold-air flow · wind speed in m/s · 04:00 Particles: cold-air flow · FITNAH-3D · Mannheim

4D Urban Climate Analysis Heat and cold air

The UDK shows how heat and cold air develop in your city, across space and over the course of the day.

FITNAH-3D calculates the diurnal cycle of a hot day at 5 m horizontal resolution. The model works with 30 vertical layers up to 2,000 m. The near-ground layers up to 60 m can be displayed as a 3D volume. The result is physically consistent 4D fields: temperature and wind fields, cold-air volume flow density, cold-air production rate and the Physiological Equivalent Temperature (PET) as a measure of perceived thermal stress.

What the 4D urban climate analysis makes visible for your city

For the entire urban area and the surrounding countryside, the analysis shows how heat and cold air develop over the course of a hot day:

  • Heat hotspots in streets as well as in residential and commercial areas
  • Cold-air generation areas
  • Cold-air corridors between the surrounding countryside and built-up districts
  • Park breeze and country breeze systems
Mannheim city centre in the strong wind analysis during a storm: above the map, particles drift with the flow through streets and across squares; their colour shows the wind speed.
Wind speed m/s
  • 0 to 1.1 m/s
  • 1.1 to 2.3 m/s
  • 2.3 to 3.4 m/s
  • 3.4 to 4.5 m/s
  • 4.5 to 5.6 m/s
  • 5.6 to 6.8 m/s
  • 6.8 to 7.9 m/s
  • 7.9 to 9.0 m/s
Wind speed in m/s · wind from west-south-west (240°) · city centre ASMUS_green · forcing: 25 m/s at 200 m height · particles: flow direction · Mannheim city centre

4D Strong Wind Analysis Storm hazards & wind comfort

The UDK shows how strong winds are steered by the urban fabric – where flows are accelerated, channelled or weakened.

ASMUS_green calculates wind flows up to the urban boundary layer, at 2 m horizontal resolution and for 12 wind directions. Buildings and trees are taken into account as obstacles to the flow: they can channel wind, accelerate it locally, or slow it down and provide shelter. Wind fields are evaluated at 2 m height (pedestrian level, important for assessing wind comfort) and at 10 m height (tree-crown and roof level, important for storm hazards).

What the 4D strong wind analysis makes visible for your city

For the entire urban area and twelve wind directions, the analysis shows:

  • Strong wind risks for buildings, trees and technical installations Which buildings, trees and technical installations – such as power pylons, traffic lights and wind turbines – are particularly exposed to strong winds?
  • Wind comfort in public spaces Where is reduced wind comfort to be expected – for example in pedestrian zones, parks, at cafés or in passageways in front of high-rise buildings?
  • 12 wind directions
  • Wind speed, gusts and turbulence
  • 2 m horizontal resolution
Mannheim Baroque Palace in an aerial image with 3D buildings, seen obliquely from above: the courtyard between the palace wings is completely sealed and light-coloured, without trees.
Current situation – Mannheim Baroque Palace with fully sealed courtyard
The same view with a fictitious planning scenario drawn into the courtyard with the Klimascanner: additional trees, an open water surface and an additional building, shown in red.
Fictitious planning scenario drawn with the Klimascanner, with additional trees, an open water surface and an additional building
The same view with the result of the Klimascanner: in the courtyard, the difference in Physiological Equivalent Temperature between the planning scenario and the current situation is coloured, mostly blue and green, i.e. cooler, strongest at the water surface and under the trees.
PET difference scenario – current (afternoon, hot summer day)
  • down to −6 °C
  • > −6 to −3 °C
  • > −3 to −1 °C
  • > −1 to 1 °C (not coloured)
  • > 1 to 2 °C
  • > 2 to 3 °C
  • > 3 °C
Result produced with the Klimascanner: difference between planning scenario and current situation, Physiological Equivalent Temperature in the afternoon of a hot summer day

Klimascanner AI-based screening

Compare planning options. Recognise effects on heat and cold air.

The KLIMASCANNER is a QGIS plugin for early planning phases. Draw buildings, green roofs, green spaces, trees or unsealing measures directly into the 3D city model. On a 5 m grid, the tool compares the current and planned situation within seconds and estimates how daytime heat, night-time cooling and cold air will change.

This quick initial assessment makes spatial differences between options visible. It lets you bring climate concerns into planning early and refine options in a targeted way. If your statutory land-use planning procedure requires an in-depth climate assessment, we are happy to support you with expert analyses and personal advice.

Before-and-after and option comparison

For heat and cold air, for example in the case of:

  • Urban development – such as new construction, conversion or open-space planning
  • Land-use changes – such as afforestation or forest conversion
  • Blue-green adaptation measures – such as unsealing, greening or water surfaces in heat hotspots
Mannheim city centre in the 3D city model with the stations of the urban climate monitoring network: at each station a card with air temperature, humidity and wind, as of 27 June 2026, 15:10; readings of around 38 to 41 °C.
Monitoring stations · air temperature, humidity, wind As of 27 June 2026, 15:10 · Mannheim
The same city centre with the monitoring stations and the real-time air temperature map interpolated from them, as of 27 June 2026, 15:10: the area between the stations is coloured throughout from yellow to red.
Monitoring stations with interpolated real-time map of air temperature As of 27 June 2026, 15:10 · Mannheim

Urban WeatherReal-time mapsUrban Weather Forecast

Urban weather in real time – and as an area-wide forecast.

An urban climate monitoring network continuously records air temperature, air and soil moisture, wind and radiation. Combined with urban climate modelling and coupling to the DWD MOSMIX forecast, area-wide maps are produced – both for the current urban weather and for the 72-hour forecast (in development), updated every six hours. They make spatial differences across the entire urban area visible – from district to district, sometimes even from one side of a street to the other. This creates a local basis for weather-sensitive decisions in everyday municipal work – for instance in event planning, green space maintenance or winter road maintenance.

Urban Weather
Real-time collection of climate, air and environmental data at the stations of the urban climate monitoring network, evaluated in the dashboard – for robust analyses and forecasts.
Real-Time Urban Weather Maps
High-resolution real-time maps of temperature, perceived temperature (PET), wind, cold air and other relevant parameters.
Urban Weather Forecast (in development)
Local, high-resolution forecasts (e.g. 3 days) for temperature, perceived temperature (PET), wind, cold air and other relevant parameters.

What the monitoring network and forecast make visible

  • How do current weather conditions differ from district to district – or even from one side of a street to the other?
  • How will the urban weather develop in the updated 72-hour forecast? (in development)
  • Where and how often do summer days, hot days and tropical nights occur?
  • Measurements
  • Modelling
  • Area-wide maps in real time
  • DWD MOSMIX forecast (in development)

Outlook

Decision Support Systems

The aim is to bundle the results of the modules into application-oriented decision aids – for climate-sensitive planning and municipal operations.

The modules are meant to improve and speed up decisions in planning and operations – or make them possible in the first place. Which decision support systems these could be for your city, and what they need to do, is something we would like to find out together with you. Let's talk.

Possible fields of application – as inspiration:

  • Winter road maintenance

    Efficient deployment planning through precise forecasts.

  • Green space management

    Needs-based irrigation and care for healthy urban green spaces.

  • Building energy management

    Optimising energy consumption, cooling demand and comfort.

  • Event management

    Risk assessment and planning for safe and successful events.

  • Heat action planning

    Early warning, protecting affected groups, steering measures in a targeted way.

  • Municipal heat planning

    Data-based analyses for a climate-adapted and efficient heat supply.

  • Transport and public transit

    Reducing weather-related risks, optimising operations.

  • Industrial processes

    Understanding weather-dependent processes, minimising risks, increasing efficiency.

  • Agriculture

    Decision support for irrigation, harvesting and adaptation strategies.

  • Urban planning / urban development

    Taking climate risks and potentials into account in spatial planning.

  • Climate adaptation

    Developing and implementing effective adaptation measures.

  • Wildfire prevention

    Recognising wildfire danger from drought, heat and wind early and planning deployments ahead.

  • And more e.g. health, civil protection, tourism, nature conservation, land-use planning and much more Your field is missing? Talk to us
Talk to us Or request an online demo

Air quality

As an additional urban climate impact area, an air quality module is conceivable in the future. We are looking for suitable cooperation partners for its development.

Technology that fits your municipality.

Developed openly, operated reproducibly – by us or by you.

Software development

The twin builds on open components – Cesium for 3D, Leaflet for 2D – and speaks open interfaces: results as OGC WMS, measurements via the OGC SensorThings API – ready to be integrated into existing GIS and geoportals. One code base serves several cities and is continuously developed further by us.

Operations

Every service runs as a container on Kubernetes, and equally with Docker Compose or Docker Swarm. Model data is stored as Cloud Optimized GeoTIFF or Zarr in object storage. The services read only the time step, height and extent they need – instead of loading entire model runs with all hours and heights. This keeps the maps fast even with large 4D data volumes, while computing load and data transfer remain low.

Hosting

We operate the twin for you – or your municipality runs it in its own infrastructure. In that case all data stays in-house, and existing GeoServer and other geodata services can be connected directly. We adapt the UDK to each city's and municipality's data and needs.

Extensible with LayerStudio

The UDK can be coupled with LayerStudio by planGIS: this lets you easily add further geodata and visualise it on the map. Optionally, you can build geodata pipelines that process data and feed it back into the twin – so geodata processes of any kind can be mapped on the web.

Get in touch

Would you like to see the twin, or do you have a question? Write to us – we reply personally. The application is not publicly accessible; we are happy to arrange an online demo.

Your contacts

  • Dr. Björn Büter, Managing Director of GEO-NET

    Dr. Björn Büter

    Managing Director, GEO-NET

    Meteorology & urban climate

  • Sven Wiemers, Team Lead Geospatial Engineering at planGIS

    Sven Wiemers

    Team Lead Geospatial Engineering, planGIS

    Software, spatial data infrastructure & operations

Behind the twin is an interdisciplinary team from meteorology, geoinformatics, software development and other disciplines.

Fields marked with an asterisk are required.

What is it about?

For example: your city, your question, a preferred date.