Warm weather may have helped suppress coronavirus. #medRxiv.org

Recent leaked comments attributed to Professor John Nicholls from the University of Hong Kong’s Department of Pathology suggest he believes weather conditions will be a key factor in the demise of the coronavirus.
Speaking during a conference call organised by Hong Kong-based brokerage firm CLSA, Professor Nicholls referenced the 2002–03 SARS outbreak and said environmental conditions – such as temperature, humidity and sunlight – are a ‘crucial factor’ in a virus’ ability to survive and infect people.
‘Sunlight will cut the virus’ ability to grow in half, so the half-life will be two-and-a-half minutes and in the dark it’s about 13–20 minutes. Sunlight is really good at killing viruses,’ he said.
‘That’s why I believe that Australia and the southern hemisphere will not see any great infection rates because they have lots of sunlight and they are in the middle of summer. And Wuhan and Beijing are still cold, which is why there’s high infection rates.
‘In regards to temperature, the virus can remain intact at 4⁰C or 10⁰C for a longer period of time. But at 30⁰C degrees then you get inactivation. And high humidity, the virus doesn’t like it either.’
But while Australia’s warmer weather has theoretically helped protect the population from a wider outbreak to this point, the coming colder months may have the reverse effect.
Professor Nicholls suggested the common cold is a better comparison to the new coronavirus than SARS or MERS, as he believes there has been a ‘severe underreporting’ of cases in China that has contributed to inflated fatality rate estimates.