Preliminary results from government lab experiments show that the coronavirus does not survive long in high temperatures and high humidity, and is quickly destroyed by sunlight, providing evidence fromcontrolled tests of what scientists believed — but had not yet proved — to be true.

A briefing on the preliminary results, marked for official use only and obtained by Yahoo News, offers hope that summertime may offer conditions less hospitable for the virus, though experts caution it will by no means eliminate, or even necessarily decrease, new cases of COVID-19, the disease caused by the coronavirus. The results, however, do add an important piece of knowledge that the White House's science advisers have been seeking as they scramble to respond to the spreading pandemic. 

The study found that the risk "of transmission from surfaces outdoors is lower during daylight," and under higher temperature and humidity conditions. "Sunlight destroys the virus quickly," reads the briefing. 

While that may provide some good news about the outlook for outdoor activities, the Department of Homeland Security briefing on the results cautions that enclosed areas with low humidity, such as airplane cabins, "may require additional care to minimize risk of transmission."

In a statement to Yahoo News, the DHS declined to answer questions about the findings and strongly cautioned against drawing any conclusions based on unpublished data.

DHSST by Sharon Weinberger on Scribd