IWXXM (ICAO Meteorological Information Exchange Model) is a format for reporting weather information in XML/GML. IWXXM includes XML/GML-based representations for products standardized in International Civil Aviation Organization (ICAO) Annex III and World Meteorological Organization (WMO) No. 49, Vol II, such as METAR/SPECI, TAF, SIGMET, AIRMET, Tropical Cyclone Advisory and Volcanic Ash Advisory. IWXXM products are used for operational exchanges of meteorological information for use in aviation.
IWXXM 1.0 was introduced in October 2013, representing METAR, SPECI, TAF and SIGMET formats as specified in International Civil Aviation Organization (ICAO) Annex III, Amendment 76. WXXM 2.0 was issued in August 2016 with the introduction of new products including AIRMET, Tropical Cyclone Advisory and Volcanic Ash Advisory,
IWXXM is regulated by WMO in association with ICAO. WXXM, governed by FAA and Eurocontrol for international products outside of those represented by ICAO or WMO, predates IWXXM by several years and all WXXM products that have been officially incorporated into IWXXM should be considered deprecated