Impact of Temperature and Relative Humidity on the Transmission of COVID-19: a Modelling Study in China and the United States
Overview
Affiliations
Objectives: We aim to assess the impact of temperature and relative humidity on the transmission of COVID-19 across communities after accounting for community-level factors such as demographics, socioeconomic status and human mobility status.
Design: A retrospective cross-sectional regression analysis via the Fama-MacBeth procedure is adopted.
Setting: We use the data for COVID-19 daily symptom-onset cases for 100 Chinese cities and COVID-19 daily confirmed cases for 1005 US counties.
Participants: A total of 69 498 cases in China and 740 843 cases in the USA are used for calculating the effective reproductive numbers.
Primary Outcome Measures: Regression analysis of the impact of temperature and relative humidity on the effective reproductive number ( value).
Results: Statistically significant negative correlations are found between temperature/relative humidity and the effective reproductive number ( value) in both China and the USA.
Conclusions: Higher temperature and higher relative humidity potentially suppress the transmission of COVID-19. Specifically, an increase in temperature by 1°C is associated with a reduction in the value of COVID-19 by 0.026 (95% CI (-0.0395 to -0.0125)) in China and by 0.020 (95% CI (-0.0311 to -0.0096)) in the USA; an increase in relative humidity by 1% is associated with a reduction in the value by 0.0076 (95% CI (-0.0108 to -0.0045)) in China and by 0.0080 (95% CI (-0.0150 to -0.0010)) in the USA. Therefore, the potential impact of temperature/relative humidity on the effective reproductive number alone is not strong enough to stop the pandemic.
Factors predictive of epidemic waves of COVID-19 in Africa during the first 2 years of the pandemic.
Wimba P, Diallo A, Klich A, Tshilolo L, Iwaz J, Etard J IJID Reg. 2025; 14:100574.
PMID: 40034656 PMC: 11874724. DOI: 10.1016/j.ijregi.2025.100574.
As air relative humidity increases, infectivity of SARS-CoV-2 decreases within water droplets.
Liu Y, Cao L, Xia Y, Pan P, Rao L, Chen B QRB Discov. 2024; 5:e6.
PMID: 39687230 PMC: 11649373. DOI: 10.1017/qrd.2024.7.
Meteorological factors, population immunity, and COVID-19 incidence: A global multi-city analysis.
Feurer D, Riffe T, Kniffka M, Acosta E, Armstrong B, Mistry M Environ Epidemiol. 2024; 8(6):e338.
PMID: 39534387 PMC: 11557119. DOI: 10.1097/EE9.0000000000000338.
Acheampong E, Husain A, Dudani H, Nayak A, Nag A, Meena E PLoS One. 2024; 19(5):e0303529.
PMID: 38809825 PMC: 11135679. DOI: 10.1371/journal.pone.0303529.
Rain, rain, go away, come again another day: do climate variations enhance the spread of COVID-19?.
Menhat M, Ariffin E, Dong W, Zakaria J, Ismailluddin A, Shafril H Global Health. 2024; 20(1):43.
PMID: 38745248 PMC: 11092248. DOI: 10.1186/s12992-024-01044-w.