Media organizations repeated the statistic, and it quickly became a standard description of the frequency of outdoor transmission. But the number is almost certainly misleading. It appears to be based partly on a misclassification of some Covid transmission that actually took place in enclosed spaces (as I explain below). The rare outdoor transmission that has happened almost all seems to have involved crowded places or close conversation. (The actual worldwide number is around 150.)

Source: New York Times May 11, 2021 10:24 UTC