Variation in Discomfort Indices in Athens, Greece, for the Period from 1901 to 2024

This study investigates long-term thermal discomfort trends in central Athens, from 1901 to 2024, using hourly data from Thissio station. Two widely used indices, Thom’s Discomfort Index and Humidex, assess human thermal sensation. Results indicate a significant increase in thermal discomfort, extending from June to September, especially during recent decades. Since 1980, days with severe discomfort have more than doubled compared to early 20th century years. In July and August, such days often exceed 20–25, especially after 2000. These findings highlight growing heat-related stress in Athens’ urban environment and underscore the need for climate adaptation strategies in Mediterranean cities.