Study: Warmer weather unlikely to slow COVID-19

As summer approaches, a new study of COVID-19 spread around the world has found that variations in heat and humidity had little to no effect on the spread of the pandemic (Source: “Summer Is Coming, but the Virus Won’t Be Going,” New York Times, May 8, 2020).

The new study found that rather than weather changes, differences in how the disease spread were instead strongly associated with public health measures like social distancing and school closures.“Only public health interventions were consistently associated with reduced epidemic growth, and the greater the number of co-occurring public health interventions, the larger the reduction in growth,” according to the study.

Several other studies have found or projected modest effects of warmer climates or the increase of sunlight in diminishing the spread of the coronavirus, but all have emphasized the need for public health interventions.

One study from researchers at the Massachusetts Institute of Technology found that humidity seemed to slow the spread of the virus. Qasim Bukhari, one of the authors of that study, said the new report was interesting, although limited by the short time span it covered. He said he and his colleagues “also stressed in our work that public health interventions are very important.” Mark C. Urban, an ecologist at the University of Connecticut, found summer weather, including ultraviolet light, had some effect on the virus and its spread, but said “social interventions have by far the most important effect.”