In the U.S., COVID transmission thrives in nicer weather

In contrast, other respiratory diseases like flu and cold are known to thrive in drier and often colder months, when lower humidity allows viral particles to linger in the air longer and people are more prone to be indoors together. The coronavirus in the U.S. is so far bucking that trend, indicating that human behaviors are likely a significant factor in transmission. The correlation between weather and coronavirus cases echoes human activity. People were about 2.5 times as likely to go out to a restaurant or bar when the temperature was 65 to 70 degrees than when it was 20 to 25 degrees, based on an analysis of anonymized cell phone data from SafeGraph from September to January. Going out to dine or drink was more dependent on the weather than other non-essential travel such as going to the gym or places of worship. Above 70 degrees case transmission falls off somewhat, while travel to restaurants and bars is higher on average. A likely explanation is that above 70 degrees, people are more prone to eat, drink and socialize outdoors, where virus transmission is known to be lower.