Abstract
In Japan, extreme summer heat has intensified in recent years, raising concerns about its effects on both physical and mental health. There is growing concern that people may refrain from going out for shopping under such conditions, potentially affecting food accessibility, which is vital for sustaining daily urban life. This study investigates how hot and humid weather affects consumer behavior by analyzing dated nationwide food purchase history data from Japan. The Discomfort Index was calculated from observed temperature and humidity data and linked to corresponding purchase records. Days in the upper and lower ranges of the Discomfort Index were extracted, and their characteristics were examined by prefecture. The analysis revealed notable differences in purchase frequency between the high-index days and low-index days. Larger behavioral differences between high and low index days were observed in northern regions of Japan, where the Discomfort Index tends to fluctuate more dramatically.
