The Impact of Meteorological Factors on the Spread of COVID‑19

Abstract

Background: Clinical studies suggest that warmer climates slow the spread of viral infections. In addition, exposure to cold weakens  human immunity.

Aim: This study describes the relationship between meteorological indicators, the number of cases, and mortality in patients with  confirmed coronavirus  disease 2019 (COVID-19).

Patients and Methods: This was a retrospective observational study. Adult patients  who presented to the emergency department with confirmed COVID‑19 were included in the study. Meteorological data [mean temperature, minimum (min) temperature, maximum (max) temperature, relative humidity, and wind speed] for the city of Istanbul were  collected from the Istanbul Meteorology 1st Regional Directorate.

Results: The study population consisted of 169,058 patients. The  highest number of patients were admitted in December (n = 21,610) and the highest number of deaths (n = 46) occurred in November. In  a correlation analysis, a statistically significant, negative correlation was found between the number of COVID-19 patients and mean  temperature (rho = −0.734, P < 0.001), max temperature (rho = −0.696, P < 0.001) or min temperature (rho = −0.748, P < 0.001). Besides, the  total number of patients correlated significantly and positively with the mean relative humidity (rho = 0.399 and P = 0.012). The  correlation analysis also showed a significant negative relationship between the mean, maximum, and min temperatures and the  number of deaths and mortality.

Conclusion: Our results indicate an increased number of COVID-19 cases during the 39-week study  period when the mean, max, and min temperatures were consistently low and the mean relative humidity was consistently high.