Increase in COVID-19 downwind following a wind change

Aerosolized SARS COV-2 is viable for at least 3–5 hours. Aerosols can rapidly become droplet nuclei and be carried long distances by wind before they settle. We hence investigated the possibility of identifying wind-assisted transmission of COVID-19. COVID-19 cases/100,000 population was calculated for hotspots and surrounding areas. Daily wind direction/speed data for hotspots was collated. Seven-day rolling averages of COVID-19 cases/100,000 population was plotted against wind direction/speed to compare case rate trends in hotspots, upwind and downwind areas. Within 14 days of the wind blowing into an area, case rate trends downwind differed from that of the hotspot. The difference compared to the hotspot could be an increase, plateau, or a slower decrease. This suggests that viral particles carried by the wind can lead to an increase in infections downwind. Research on ways to reduce aerosol transmission in the community is urgently needed.