ទិន្នន័យគុណភាពខ្យល់ផ្តល់ដោយ៖ the World Meteorological Organization - surface synoptic observations (WMO-SYNOP) (worldweather.wmo.int) and the Sundsvall municipality (Sundsvalls kommun) (sundsvall.se) and the European Environment Agency (eea.europa.eu)