ECMWF IFS Ensemble

The ECMWF IFS Ensemble (ENS) provides 50 perturbed-forecast runs with slightly varied starting conditions.

Live Forecast Data

• Global coverage at 25 km resolution (720x1440 grid)

• Four daily runs (00, 06, 12, 18 UTC)

• 00/12 UTC runs: 360h forecast (15 days); 06/18 UTC runs: 144h forecast (6 days)

• 3-hourly time steps to 144h, then 6-hourly out to 360h

• Real-time data access via Python SDK or REST API

Technical Specifications

Available Weather Parameters

ECMWF ENS uses standardized variable naming conventions. For full details on the naming structure, see Weather Variable Naming.

Code	API Name	Description	Units
2t	air_temperature_at_height_level_2m	Air temperature at 2m	Kelvin
10si	wind_speed_at_height_level_10m	Horizontal wind speed at 10m	m s⁻¹
100si	wind_speed_at_height_level_100m	Horizontal wind speed at 100m	m s⁻¹
10wdir	wind_direction_at_height_level_10m	Horizontal wind direction at 10m	Degrees true
100wdir	wind_direction_at_height_level_100m	Horizontal wind direction at 100m	Degrees true
msl	air_pressure_at_mean_sea_level	Mean Sea-level Pressure	Pa
tp	precipitation_amount_sum_1h	Total Precipitation	mm m⁻²
ssrd	surface_downwelling_shortwave_flux_sum_1h	Surface solar downward irradiance	J m⁻²
z	geopotential_at_pressure_level_50000Pa	Geopotential at 500 hPa pressure level	m² s⁻²

Hindcast Data

Data Access: Hindcasts are available via API or SDK. For bulk, grid-based access, please contact [e-mail].

Model	Spatial Extent	Temporal Extent
ECMWF ENS	Global, 25 km resolution (720x1440 grid)	2025-09-01 - today