Dew-point measurements were made using a Campbell Scientific Dew point hygrometer. The measurements were taken from samples collected on the roof of the FAGE container. The dataset provide dew point in degrees C at one minute averaging periods. The work was carried out at Halley Station in 2005, as part of the CHABLIS project (Chemistry of the Antarctic Boundary Layer and the Interface with Snow). CHABLIS ran from 2001-2006.