New evidence suggests UV rays from sunlight can kill the corona virus.

This gives hope that spread of the virus will slow dramatically as summer arrives.

William Bryan, a science and technology advisor to the Department of Homeland Security, told White House reporters about new findings.

He explained that research has shown that ultraviolet rays, high temperatures and humidity significantly reduce the life of the virus on surfaces and in the air.

The paper on the study has not yet been released for peer review.

Bryan did show slides that summarized the major findings from experiments done by the National Biodefense Analysis and Countermeasures Center in Maryland.

It showed the virus’s half-life - the time required to reduce its amount by half - is affected by heat and humidity.

When the temperature was 70-75 degrees and below 20% humidity, the virus's half-life was 18 hours on a non-porous surface.

But the half-life dropped to 6 hours when humidity rose to 80%.

When sunlight was added, it dropped to 2 minutes.

UV has a sterilizing effect because the radiation damages the virus’s genetic material and hinders replication.

Another study by ecological modelers at the University of Connecticut found similar results to the DHS study.

Still unknown is the exact wavelength and duration of exposure that is most effective in killing the covid-19 virus.