TdM > MSC Data > Aviation Weather Data > Aviation Weather Data in IWXXM Format on the MSC Datamart

Aviation Weather Data in IWXXM Format

This page describes specialized aviation bulletins distributed in the IWXXM format, an ICAO meteorological information exchange model introduced in November 2013 by Amendment 76 to ICAO Annex 3, allowing States to exchange their OPMET (Operational Meteorology) not only in TAC (traditional alphanumeric code) format but also in Extensible Markup Language (XML) and, more specifically, in Geographic Markup Language (GML).

IWXXM information exchange became a recommendation through Amendment 77 to ICAO Annex 3 in November 2016 and a standard in November 2020, as specified in Amendment 78 to ICAO Annex 3.

This page describes both the aviation meteorological data in IWXXM format available on the MSC Datamart and the schema used to encode Canada-specific data.

Data Address

Data from the MSC Datamart can be automatically retrieved using the Advanced Message Queuing Protocol (AMQP) as soon as it becomes available. An overview and examples for accessing and using the Meteorological Service of Canada’s open data is also available.

The data is available via the HTTPS protocol. It can be accessed using a standard web browser. In this case, a list of links providing access to an XML file is displayed.

Meteorological data in IWXXM format can be found at the address:

https://dd.weather.gc.ca/today/aviation/iwxxm/{product}/{code_issuer}/{HH}

With:

product : Aviation product (see list below)
code_issuer: Code of the airport that reports the observation
HH: Data transmission hour (UTC)

Aviation product	Bulletin type	File header
vaa	Volcanic Ash Advisory	A_LUCN
qvaci	Quantitative Volcanic Ash	To be determined
taf	Aerodromes forecasts (TAF)	A_LTCN
metar	Aerodrome routine (METAR)	A_LACN
speci	Special meteorological report (SPECI)	A_LPCN
airmet	AIRman's METeorological Information (AIRMET)	A_LWCN / A_LWNT
sigmet	SIGnificant METeorological Information (SIGMET)	A_LSCN-A / A_LYCN / A_LVCN

Canada uses version 3.0.0 of the WMO IWXXM schemes available at the following address: https://schemas.wmo.int/iwxxm/

Canada also uses extension to provide additional meteorological elements or to meet national requirements. The Canadian extension schemas are available at the following address: