What is ICON weather model and how it works

The ICON weather model is one of the several major forecast models in the world. Actually, it is not one, but a whole series of models where the main ones are ICON-D2, ICON7 and ICON13. In this post, you will learn about ICON model for sports and outdoors, its working principle and main features, and where to find the weather forecast by this model.

What is ICON weather forecast model?

The ICON (Icosahedral Nonhydrostatic) is a suit of models created by the German national weather service or DWD (Deutscher Wetterdienst). There are at least three major ICON models: ICON-D2 for Central Europe, ICON7 for Europe as a whole, and ICON13 for the world. So it is both hyper-local, regional and global weather forecast model.

Thanks to its high resolution, ICON-D2 takes into account the terrain and also predicts severe weather better comparing to other regional models, which makes it excellent for adjusting your plans for today and tomorrow.
In Europe, ICON7 it is considered to be even more accurate than the ECMWF also due to the better resolution.
ICON13 is the world's third most popular global weather model after the same ECMWF and American GFS. It is in competition with them.

In general the most important variables of the ICON are air density and virtual potential temperature, horizontal and vertical wind speed, humidity, cloud water, cloud ice, rain and snow.

Its small-scale part includes the COSMO model, which was fully integrated into the ICON in 2020.

The official website of the model is Dwd.de.

What are the main features of ICON weather model and how it works?

The ICON model has various resolutions: ICON-D2 — 2.2 km, ICON7 — 7 km, and ICON13 — 13 km. The resolution is the distance between two points of the weather model grid. Bigger resolutions of 50 to 10 km in size are usually deployed in relatively flat terrains, while mountain ranges require the nodes to be a lot closer to each other, usually 5, 2, or 1 km.

The forecast depth of ICON weather model: ICON-D2 — 2 days, ICON7 — 5 days, and of ICON13 — 7.5 days. The depth of the weather forecast is the number of hours or days for which the forecast is made. As a rule, the lower the depth, the more accurate the forecast.

The ICON forecast step for all ICON models 1 hour. The forecast step is for how long you can see a forecast in the application or on a website. There are two main step types: 1 h and 3 h.

The ICON expected update is 8 times a day for ICON-D2, and 2 times a day for both other models, too. The update frequency of the forecast is the regular time interval after which new forecast data is received from the supercomputers. There are models with 24 times a day updates, but in general, the frequency of the updates of weather models is 1, 2, or rather 4 times a day.

Let's sum up the main features of ICON model:

Resolution: ICON-D2 — 2.2 km, ICON7 — 7 km, ICON13 — 13 km
Forecast depth: ICON-D2 — 2 days, ICON7 — 5 days, ICON13 — 7.5 days
Step: 1 h for all models
Expected update: ICON-D2 — 8 times a day, ICON7 and ICON13 — 2 times a day

Where to get the weather forecast from the ICON model in the Windy.app?

The ICON weather model is also the main model in Windy.app among 10+ other models. In the app, the model has the same 2.2, 7 or 13 km resolution depending on the type of the model: Central Europe, Europe or global. To get a weather forecast from ICON:

1. Open your favorite or the nearest spot to your current location in the app from the Home screen or Wind and precipitation map. To see the nearest spots, allow the app to see your location in Settings.

ICON weather model in the Windy.app for iOS

For exampe, let's take Lo Stagnone kitesurfing spot in Italy:

ICON weather model in the Windy.app for iOS

2. Choose ICON-D2, ICON7 or ICON13 in the slider under the Wind Rose:

icon7-weather-model-lo-stagnone-italy-windyapp-ios

ICON weather model in the Windy.app for iOS

3. Read the weather forecast from the ICON for your particular sport or outdoor activity. In Windy.app you can get the following weather parameters from the ICON:

ICON-D2

Weather condition
Air temperature
Wind speed
Wind gusts
Wind direction, cardinal
Wind direction, °
Atmospheric pressure at sea level
Rain and snow

The aforementioned weather elements are available at the Lite Weather Profile for general weather forecasting. In addition, you can also have relative humidity in Bike and Air weather profiles:

ICON weather model in the Windy.app for iOS

Also you can get three useful charts: Rain and snow in the same Lite Weather Profile, Clouds and Precipitation, and separately Clouds (cloud coverage) in Expert and Fish weather profiles:

ICON weather model in the Windy.app for iOS

ICON7

Wind speed
Wind gusts
Wind direction (both cardinal and degrees)
Air temperature
Atmospheric pressure at sea level

ICON weather model in the Windy.app for iOS

In addition, you can have the general weather condition in the Lite Profile you can choose by an icon right to weather models: sunny, rainy, cloudy, etc. from the ICON. They are represented like this:

general-weather-conditions-lo-stagnone-italy-windyapp-ios

ICON weather model in the Windy.app for iOS

In Fish Pro Weather Profile, you can also get the useful Atmospheric pressure at sea level chart:

atmospheric-pressure-lo-stagnone-italy-windyapp-ios

ICON weather model in the Windy.app for iOS

ICON13

Wind speed
Wind gusts
Wind direction (both cardinal and degrees)
Air temperature
Atmospheric pressure at sea level
Clouds
Precipitation (rain)
Snow precipitation
Snow depth (in Snow Weather Profile)
Freezing level
Spot altitude
CAPE Index (in Air Weather Profile)

ICON weather model in the Windy.app for iOS

In addition, you can also have the general weather condition in same Lite Weather Profile: sunny, rainy, cloudy, etc. from the ICON. They are represented the same way:

ICON weather model in the Windy.app for iOS

Also you can get three useful charts in the same Fish Pro Profile and Expert Profile, choosing ICON13 model:

Freezing level chart
Rain and snow chart
Atmospheric pressure at sea level chart

ICON weather model in the Windy.app for iOS

freezing-level-lo-stagnone-italy-windyapp-ios

ICON weather model in the Windy.app for iOS

4. Choose or delete one of these weather parameters using the Customization feature. That's how you will make your own custom weather profile in Windy.app:

ICON weather model in the Windy.app for iOS

5. Compare weather data from ICON models to other models in Windy.app using special Pro feature Compare Mode.

ICON weather model in the Windy.app for iOS

6. Compare ICON weather forecast accuracy with other weather models thanks to special Windy.app feature based on data directly from weather stations. The weather stations are always located on the same spot's screen: