Radiosonde observations provide a good data source for examining the long‐term trend of atmospheric water vapour, temperature and cold point tropopause ( CPT ). In this article, precipitable water vapour ( PWV ) and surface temperature from the Hong Kong radiosonde station over the period of 1973–2012 are analysed. We find that the atmospheric water vapour in Hong Kong in the layers from the surface to approximately 1181 m, fr...