Met Office 4D-Trajectory 1.0.0


The Met Office 4D Trajectory API service supplies global meteorological data for tailored flight trajectory requests, to support flight planning services and software products. The benefits of exploiting 10km resolution meteorological data for flight planning and in-flight decision making include:

  • Save fuel costs
  • Reduce CO2 emissions
  • Improve Flight Management Computer (FMC) calculations to save fuel
  • Supply notifications of weather hazards for situational awareness and improved safety

Trajectory requests allow the user to specify a latitude, longitude, atmospheric height, date/time and weather parameters, to map meteorological data to a flight trajectory. (See API Specification)

Two API’s are available to supply the following weather parameters:

  • The 'MAIN' dataset includes our core weather parameters for aviation operations (Winds, Temperature, Relative Humidity).
  • The 'HAZARDS' dataset includes turbulence severity
    • Icing and CB Cloud Base/Top Height could be made available in due course
    • Convection data is currently available in 17km resolution, please note that the Met Office is currently undertaking validation work to supply 10km resolution CB data.

This API service conforms to the Open Geospatial Consortium Environmental Data Retrieval (EDR) Specification, delivering data in coverage JSON format.

Available March 2022.

Service Type
Lifecycle Stage
Business Activity Type
Intended Consumer
Information Exchange Category
Application Message Exchange Pattern
State ICAO Nationality Letters
ICAO Region
Geospatial Categorisation Description
Global based on gridded data
In-Operation Date
Met Office

The Met Office is the sole Air Navigation Service Provider (ANSP) certificated by the UK Civil Aviation Authority to provide and disseminate a range of aviation forecast products and services, in accordance with ICAO Annex 3 to the Chicago Convention, Meteorological Service for international Air Navigation.

ICAO’s Annex 3 provides the main regulatory framework against which the UK is obliged to provide meteorological services, and which the Met Office delivers Met Services against. This ensures that the UK meets its obligations to ICAO to provide safe, efficient and regular air travel.

These services fall into the following main categories:

a) UK services.

b) The World Area Forecast System (WAFS), as provided by World Area Forecast Centre (WAFC) London, in coordination with colleagues in the US.

c) SADIS (Secure Aviation Data Information Service).

d) The Volcanic Ash Advisory Centre (VAAC) London.

In addition to the ICAO Annex 3 determined services, a range of discretionary services that are determined as a requirement in the UK are also provided. Specific services such as Aviation R&D and the provision of information to NATS are examples of this.

Provider Type

To report incidents on services in operation, contact the 24/7 Weather Desk at or +44 330 135 0000.

Revision Save Date
Fri, 10/27/2023 - 12:00
Schema version