SADIS WAFS SIGWX API 1.0
Current JSON

Abstract

The SADIS World Area Forecast Service (WAFS) SIGWX API (the Service) supplies packaged bulletins of Significant Weather data in response to tailored API requests submitted by an end user. This data is provided under the remit of International Civil Aviation Organisation (ICAO) and can be used to support activities related to aviation.

The Service is provided in accordance with ICAO Annex 3 – Meteorological Service for International Air Navigation and the PANS-MET – Procedures for Air Navigation Services – Meteorology (Doc 10157) and comprises of:

  • Metadata relating to the description and operation of the API.
  • A list of the data payload collections available to request.
  • Four data sets per model run:
      • XML data packaged as IWXXM (per timestep) for ingestion into visualisation software.
      • Polar charts (North and South Pole individually) per timestep – for validation purposes only.
      • Mercator (Global) charts per timestep – for validation purposes only.

Key Features:

  • Data containing all Significant Weather features: CB Cloud, Turbulence, Icing, Tropical Cyclones (up to T+24), Jets, Fronts, Volcanic Events, Tropopause levels and Nuclear events.
  • The forecast period extends out to 48 hours (T+6 through to T+48 at 3-hour intervals).
  • Flight levels FL100-FL600
  • New data produced 4 times per day (0000, 0600,1200,1800).

SADIS WAFS SIGWX API is part of the SADIS API family of offerings developed by the Met Office, which use the Open Geospatial Consortium Environmental Data Retrieval (OGC-EDR) framework. SADIS API includes:

  • SADIS WAFS Gridded Data API
  • SADIS OPMET API

In the event of operational issues with the Service, KKCI (NOAA) data is also available on the WAFC Washington's WIFS API to provide backup.

Service Type
SWIM_COMPLIANT
Life Cycle
OPERATIONAL
Business Activity Type
AIRSPACE_ORGANISATION_AND_MANAGEMENT
Intended Consumer
AERONAUTICAL_INFORMATION_SERVICE_PROVIDER
AIR_TRAFFIC_SERVICE_PROVIDER
Information Exchange Category
AERONAUTICAL_INFORMATION_EXCHANGE
METEOROLOGICAL_INFORMATION_EXCHANGE
Application Message Exchange Pattern Entity
SYNCHRONOUS_REQUEST_REPLY
State ICAO Nationality Letters
EGRR
ICAO Region
EUR
Geospatial Categorisation Description
Worldwide coverage, where available, of data sets that are disseminated internationally over the Aeronautical Fixed Service and from Worldwide coverage based on gridded forecast data.
In-Operation Date
09-Apr-2025
Provider
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 WAFC Washington.

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
REGULATED_METEOROLOGICAL_SERVICE_PROVIDER
Support

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

Point of Contact
Operational need for SADIS WAFS SIGWX API

The service is provided in accordance with ICAO Annex 3 – Meteorological Service for International Air Navigation, and the PANS-MET – Procedures for Air Navigation Services – Meteorology (Doc 10157) from November 2025

Data Type

Allow service consumers to request SIGWX API data.

Data Type - Significant weather forecasts in IWXXM, and .png format.

Either time-stepped (3 -hourly) forecast data OR information about what data is available and how the API service works in .json

OAUTH2 Client Credential/Bearer Token

Accessing the service is subject to prior approval by the SADIS Manager and agreeing to our terms and conditions. 

Access is based on OAUTH2 Client Credentials using Client ID and Secret to retrieve a Bearer Token. Login credentials must be set up in advance of first-time use.

Access to WAFC London's SADIS WAFS SIGWX API does NOT include reciprocal access to WAFC Washington's WIFS API service. Should you wish to access WAFC Washington's WIFS API, then you must apply directly via their website: https://aviationweather.gov/wifs/

Check Headers

The API makes use of standard HTTP headers, as specified in the SWIM Yellow Profile, WS Light Service Interface Binding.

Service Consumption Constraint

Usage is limited as per our Throttling standard policies.

Limited to either:

200 requests per day per unique user.

or

1000  requests per day per unique user.

Service Level Agreement

The WAFC London SADIS Manager periodically reports service performance and availability statistics to ICAO. 

Forecast data itself is verified by the Met Office Verification team annually.

To meet requirements from ICAO, Aviation Industry users and stakeholders, the Service is highly available: 

  • EDR API requests from qualified end users (authorised and authenticated via APIM) can be submitted at any time, and the Service will provision a response payload 24/7/365. 

  • The payload response of SIGWX data matches the item(s) requested by qualified end users (authorised and authenticated via APIM).

  • The WAFS SIGWX data sets should be available to qualified and authorised users via the EDR API no later than 7 hours after the nominal model run time. 

Capacity of Service

The service has been load tested. It remains performant with 1000 unique end users concurrently making API requests for 20 minutes and being provisioned with payloads.

Time behaviour of Service

> 92% of responses to API requests will be made within 5 seconds of submission.

Request/Response latency is exposed in the SIGWX health monitoring dashboard available to the Met Office support teams 

Availability

The service updates 24/7/365. The Met Office Supercomputer generates new model updates every 6 hours, and the service only exposes forecast data from the latest model update. 

Performance is monitored via synthetic ‘canaries' against these availability targets measured per calendar month using Met Office download speed:

  • 99% of the time, a valid EDR API request from a qualified end user will be successfully fulfilled (i.e., returned the appropriate requested payload).

  • 99.2% of the time, a valid EDR API request from a qualified end user will be provisioned within 2 minutes.

Recoverability

Technical support is available 24/7, although on a 'best efforts only' basis outside normal working hours (08:00-17:30 GMT Monday to Friday, except Bank Holidays).

In the event of operational issues, we will instruct our users to access their usual data sets from the WIFS API, which is operated by WAFC Washington. Both SADIS and WIFS API offerings have been harmonised to enable this fail-over process.

SADIS FTP can also be used to provision WAFS data sets to existing qualified end users until 2028 when SADIS FTP will be retired.

Confidentiality

The Service adheres to SWIM Yellow Profile - Infrastructure Capabilities Binding requirements.

The system does not store or manage any personal data. Threat analysis confirmed that loss of confidentiality is deemed Low Risk.

Integrity

The Service adheres to SWIM Yellow Profile - Infrastructure Capabilities Binding requirements.

The Met Office also has robust Cyber Security protocols in place. In the unlikely event of a security breach impacting the integrity of the data, the service will be suspended, and we would notify users to fail over to WAFC Washington's WIFS SIGWX Data service until security has been fully restored. 

APIM

API Manager - the API management platform used for Authentication and Authorisation that is integrated with the Service. APIM acts as the 'front door' of the Service for our users.

EGRR

The identifier code for the UK Met Office as the forecast originating centre. “EGRR data” refers to forecast data produced by the Met Office.

ICAO

International Civil Aviation Organisation.

NOAA

The National Oceanic and Atmospheric Administration; the forecast centre for the USA.

OGC

Open Geospatial Consortium. OGC is a consortium of experts committed to improving access to geospatial, or location information.

SADIS

Secure Aviation Data Information System (SADIS), which supplies World Area Forecast System (WAFS) and OPerational METeorology (OPMET) data to aviation users in Europe, Africa, and parts of Asia. SADIS is delivered and maintained exclusively by the Met Office.

SADIS is a data library. It does not process/visualise data. It makes data available for extraction, processing and/or visualisation by end user systems.

Two versions of SADIS are currently available, the SADIS FTP (which will be retired in 2028) and the new SADIS API.

Timestep

Means “forecast period”. A period of time for which forecast data is given, usually expressed as the number of hours after the model run time, e.g. T+6 means 6 hours after the model run time.

WAFC

World Area Forecast Centre.

The Met Office is one of only two World Area Forecast Centres (WAFC) and is known as WAFC London - the other is WAFC Washington (NOAA).

WAFS

Worldwide Aviation Forecast System.

WIFS

WIFS is the World Area Forecast System (WAFS) Internet File Service, a service provided by the United States to support international flight operations.

Information
SADIS WAFS SIGWX API

The Met Office operates the SADIS WAFS SIGWX API in its role as WAFC London, to support air navigation in Europe, Africa, the Middle East and Asia. The service supplies Global datasets tailored to API requests by an end user.

  • Data source: from WAFC London (or WAFC Washington in backup)
  • IWXXM collection for operational use, PNGs (Polar and Global) for validation purposes.
  • Data sets are refreshed following model updates every 6 hours.
Security Mechanism

TLS 1.2

The service uses HTTPS over TLS 1.2 to provide integrity and confidentiality.

Service Monitoring for SADIS WAFS SIGWX API

The Service is monitored and has automated alerts that go to 24/7 Met Office support teams. However, no consumer visible monitoring capabilities are provided.

The generation of observational data and subsequent bulletin creation are triggered on the successful ingestion of requisite base components (push). Appropriate logging, monitoring and alerting are in place 24/7.

5-minute Synthetic Canary

A heartbeat service is used to periodically check the status of the service and determine whether it is available. This runs every 5 minutes 24/7 and checks the availability of SIGWX data.

EDR Response Codes

 

EDR Response Code Table

EDR Response code Code Meaning Impact and suggested actions
200 (OK) The request is successful. Expected behaviour, you can access the data.
302 (Found) Redirect status response code indicating that the resource requested has been temporarily moved to the URL given by the Location header.

Expected behaviour for retrieving {itemId} payloads. Follow this redirect to pick up your payload.
401 (Unauthorized Request) You are not authorised to access the service because our server requires user authentication. You cannot access the data due to invalid authorisation. Please check that your authorisation token is valid and has not expired, and try again.
403 (Forbidden) The request has been rejected because you do not have the rights to access or view the content. You cannot access the data due to invalid authorisation. Please check that your authorisation token is valid and has not expired, and try again.
404 (Not Found) The request is invalid. You cannot access the data because your request is not formulated correctly. Please check the validity of your request against the SADIS API - User Guide, Section 2.2 and Chapter 4.
408 (Request Timeout) The request you sent to the system took longer than the server was prepared to wait. You cannot access the data. Please try again. It is very unlikely that you encounter this error code. If the error persists, please contact our Support teams.
500 (Internal Server) While the request appears to be valid, the server failed to complete it. You cannot access the data. Please try again. If the error persists, please contact our Support teams.
502 (Bad Gateway) While the request appears to be valid, the server failed to complete it. You cannot access the data. Please try again. If the error persists, please contact our Support teams.
504 (Gateway Timeout) While the request appears to be valid, the server failed to complete it. You cannot access the data. Please try again. If the error persists, please contact our Support teams.
SADIS WAFS SIGWX API

Provides meteorological Significant Weather data in response to API requests submitted by an end user. This data is provided under the remit of the International Civil Aviation Organisation (ICAO) and can be used to support activities related to aviation.

PROVIDER_SIDE
SYNCHRONOUS_REQUEST_RESPONSE
Operations
HTTP GET

The Service provides Significant Weather forecasts as IWXXM and PNG response payloads. Within each request.

The Service also provides end users the ability to request metadata about the meteorological forecast included in the forecasts, returning a response in .json format.

Synchronous: Transactions are synchronous.

TI Protocol Method: HTTP GET

Precondition: Consumers must be authenticated and authorised via the Met Office API Management (APIM) Developer portal.

Processing consideration: The service shall provide only the latest available data.

Idempotent
IDEMPOTENT
Operation Message
HTTPS GET
GET /collections/{collectionId}

URL: https://gateway.api-management.metoffice.cloud/sadis-wafs-sigwx/1.0/col…{collectionId}

Querying this end point returns metadata information in JSON format about one of these specific collections {collectionId}:

  • egrr_iwxxm_forecasts
  • egrr_charts_global
  • egrr_charts_northpole
  • egrr_charts_southpole
  • kkci_iwxxm_forecasts
  • kkci_charts_global
  • kkci_charts_northpole
  • kkci_charts_southpole
Resource Type
REST_RESOURCE
Url

https://gateway.api-management.metoffice.cloud/sadis-wafs-sigwx/1.0/col…

Get / collections/{collectionId}/locations/{locationId}

Url: https://gateway.api-management.metoffice.cloud/sadis-wafs-sigwx/1.0/col…{collectionId}/locations/{locationsId}

Return data in the collection for the location defined by locationId.

{collectionId}/locations/{locationId}?datetime={time}- Where {collectionId} could be:

  • egrr_iwxxm_forecasts
  • egrr_charts_global
  • egrr_charts_northpole
  • egrr_charts_southpole
  • kkci_iwxxm_forecasts
  • kkci_charts_global
  • kkci_charts_northpole
  • kkci_charts_southpole

 

Where {locationId} could be:

  • Global

For example: https://gateway.api-management.metoffice.cloud/sadis-wafs-sigwx/1.0/col…

Will return all available timesteps available for the EGRR IWXXM collection.

Resource Type
REST_RESOURCE
Url

https://gateway.api-management.metoffice.cloud/sadis-wafs-sigwx/1.0/col…

WS Light

The Service Interface Binding is SWIM Yellow Profile Compliant, using WS Light enabling HTTP GET requests and associated responses.

IPV4_SECURE_UNICAST

The Service implementation conforms with IPV4_SECURE_UNICAST as part of SWIM Yellow Profile requirements.

References
Revision Save Date
Thu, 05/22/2025 - 12:57
Schema version
v2