The file includes calculations of the daily values (mean, maximum, minimum) of two widely accepted indices of thermal discomfort, Thom’s Discomfort Index (Thom, 1959) and Humidex (Masterton and Richardson, 1979), from 1901 until 2024, for Athens, Greece. The calculations of indexes were based on the use of hourly temperature and relative humidity values from the historic climate station of the National Observatory of Athens (the oldest climate station in the country) located at the Hill of Nymphs in Thissio (latitude: 37.972 N, longitude: 23.717 E, altitud...