ItaliaMeteo ARPAE ICON-2i
Open data weather forecasts from the Italian weather service ItaliaMeteo
Data Sources
This API provides access to the ICON-2I model from ItaliaMeteo-ARPAE.
| Weather Model | Region | Spatial Resolution | Temporal Resolution | Forecast Length | Update frequency |
|---|---|---|---|---|---|
| ICON 2I |  | 0.02° (~2 km) | Hourly | 3 days | Every 12 hours |
Native Model Variables
ICON-2I directly predicts the fields listed below. Open-Meteo retains these fields or uses them to calculate more convenient API variables. ICON-2I provides native weather codes, direct solar radiation and dew point rather than relative humidity.
| Native ICON-2I field | Level | Use in the Open-Meteo API |
|---|---|---|
| Temperature and dew point | 2 m, pressure levels | temperature_2m, relative humidity and dew point |
| U and V wind components | 10 m, pressure levels | Wind speed and direction |
| Wind gusts | 10 m | wind_gusts_10m |
| Mean sea-level pressure | Mean sea level | pressure_msl and derived surface pressure |
| Total, grid-scale and convective rain and snow | Surface | precipitation, rain, showers, snowfall |
| Direct solar radiation | Surface | Global, direct, diffuse radiation, DNI and GTI |
| Cloud cover total, low, mid and high | Surface | cloud_cover and the individual layers |
| Weather code (WW) | Surface | weather_code (with temperature-based corrections) |
| CAPE, convective inhibition, lightning potential, freezing level, snow depth | Surface | Corresponding API variables and weather-code inputs |
| Geopotential, vertical velocity and relative humidity | Pressure levels | geopotential_height, vertical_velocity, pressure-level cloud cover |
| Soil temperature and moisture | Multiple depths | Soil temperature and moisture variables |
Visibility is not available for this model.
Derived Variables
ICON-2I publishes native weather codes, direct solar radiation, wind gusts, cloud cover layers, CAPE, convective inhibition and lightning potential. Open-Meteo derives the remaining API variables from these native fields.
| Derived Variable | How it is derived? |
|---|---|
| Wind speed and direction | Calculated from the native U and V wind components at 10 m and on all pressure levels. |
| Relative humidity and dew point | ICON-2I publishes dew point; relative humidity is computed from temperature and dew point, and dew point is then recomputed on request. |
| Weather code corrections | The native ICON WW code is adjusted so precipitation codes without precipitation fall back to cloud cover, and snow and rain codes swap based on temperature and snow line. |
| Rain, showers and snowfall | Split from the native grid-scale and convective rain and snow fields. Snowfall converts the water equivalent with 0.7 cm per mm. |
| Diffuse radiation | Global minus native direct radiation. DNI, GTI and instant values follow from solar geometry. No radiation separation model is required. |
| Surface pressure | Calculated from mean sea-level pressure, 2 m temperature and terrain elevation. |
| Vertical velocity | Native omega in Pa/s converted to geometric velocity in m/s using the temperature at each pressure level. |
| Pressure-level cloud cover | Estimated from native pressure-level relative humidity. |
| Apparent temperature, ET₀, sunshine duration and wet bulb temperature | Combine temperature, humidity, wind speed and solar radiation. ET₀ follows the FAO-56 Penman-Monteith equation; sunshine duration counts time with DNI above 120 W/m². |
Sunrise, sunset, daylight duration and the day-or-night flag are astronomical calculations. Daily values are aggregated from hourly data.
API Documentation
For a detailed list of all available weather variables please refer to the general Weather Forecast API.