Climate and temperature have long been considered in relation to human diseases and mortality. In this study, we investigated whether daily temperature and humidity and patients' personal history affect the volume of peritonsillar abscesses (PTAs). We included 52 patients with PTAs who were admitted to the emergency department of the study hospital; their computed tomography data were analyzed, and PTA volume was measured. We investigated the possible correlation between PTA volume and mean/minimum/maximum temperature and humidity. Furthermore, we obtained personal history data, including information on drinking status, smoking status, dental problems, and patients' treatment experiences at local clinics before visiting the emergency department. The mean PTA volume was 3.93 mL, which was significantly correlated with temperature differences between 1 and 2 days before hospitalization and the day of hospitalization (P < .05) and also with a lack of treatment experience at local clinics (P < .001). However, no significant correlation was noted between PTA volume and the mean/minimum/maximum temperature and humidity on the day of hospitalization (P > .05). Similar findings were obtained for drinking status, smoking status, and dental problems (P > .1). PTA volume appears to be strongly associated with temperature differences between 1 and 2 days before hospitalization and the day of hospitalization. Patients with treatment experience at local clinics exhibited substantial increases in PTA volume. Thus, an increased PTA volume may be observed in patients who visit the emergency department without any treatment experience at local clinics or from environments that differ considerably from their current environment in terms of temperature.