ទិន្នន័យគុណភាពខ្យល់ផ្តល់ដោយ៖ the World Meteorological Organization - surface synoptic observations (WMO-SYNOP) (worldweather.wmo.int) and Natur Vårdsverket - Swedish Environmental Protection Agency (naturvardsverket.se) and the European Environment Agency (eea.europa.eu)