Surface Dew/Frost Forecast
The dew/frost forecast map shows areas where dew or frost is likely 24 hours after the time indicated on the map. Dew forms when the dew point reaches or is close to the actual air temperature. The following temperature ranges indicate the difference between the temperature and the dew point. Areas coloured in yellow, orange and red are expected to be dry with no dew forecast. Yellow indicates a 5-10 degree Celsius difference, orange a 10-20 degrees C difference, red a 20-30 degrees C difference, and dark red a difference of more than 30 degrees C. Grey corresponds to a 3-5 degrees C difference (labelled as dew less likely). Light blue corresponds to a difference of 1-3 degrees C (labelled as dew possible). Areas coloured dark blue represent areas where dew is likely. The white areas correspond to cases when the temperature is expected to be 1°C or less (labelled as frost-likely). This map takes into consideration only large-scale dew/frost formation. Local cooling effects induced by valleys, gorges, or rivers have not been considered.