This dataset contains Humidity Adjusted Cooling and Heating Degree Days in Saudi Arabia’s Regions from 1990-2019. Follow datasource.kapsarc.org for timely data to advance energy economics research.Source: Author’s CalculationWe calculate humidity-adjusted CDD and HDD, NOAA’s National Weather Service (NWS) Heat Index (HI) is used to measure the human-perceived equivalent temperature.It is calculated through a multiple regression analysis of Steadman’s equations for wind and solar radiation by using only two independent variables, ambient temperature (T) and relative humidity (Rh).To calculate the NWS HI, the regression analyses is applied to the relationships among wind and solar radiation with independent variables T and Rh.The dataset could be used by researchers who model residential electricity demand, studies of energy efficiency, and policymakers to base their potential policy scenarios on weather conditions.