The data set contain localized current and future heat waves for use in thermal modelling of buildings across the UK. The weather data is in the format of EnergyPlus Weather (.epw) which was developed for building simulation programs. The building simulation weather file contains 8,760 hours of all the thermally related weather variables such as dry-bulb temperature, dewpoint temperature, relative humidity, atmospheric pressure, direct and diffuse solar radiation, wind direction and speed. The weather file contains an Example Extreme Week (EEW), i.e., weather data from an extremely hot seven-day contiguous period. The initial date of the EEW is mentioned in the comment line of the weather file. The weather files are available for current and future time slices: 1970s (1961 to 1990) and 2080s (2079 to 2099) with three return periods (10, 20 and 50 years) and one baseline period. Hence, there are six extreme weather files and one baseline weather file in each subfolder. These weather files are available at a 5 km grid resolution across the UK. In total, there are 11326 grid locations aggregated into three zip files: TYPE_J01 (3,775 grids), TYPE_J02 (3,775 grids), and TYPE_J03 (3,776 grids). The grid number, latitude, longitude and elevation for each of 11326 grid locations can be found in ‘GridID_Lat_Long_Elev.csv’.