At this point in the pandemic, it has become clear that a warm climate, at least up to ~32 °C (90 °F) is not by itself sufficient to prevent local
transmission of the coronavirus responsible for COVID-19. Sustained community transmission has already been observed in a variety of countries with
warm climates.
Whether a warm or sunny climate might still have a mild effect on slowing transmission is unclear. Some of the above charts suggest that a mild effect
is possible. However, the growth rates observed across a variety of climates do not show signs of a strong relationship or limitation across the range
of weather conditions that have been observed so far.
One explanation may be that a majority of transmission simply occurs indoors during close interactions with family, friends, and coworkers. A Chinese
contact tracing study looking at over 7000 cases with known routes of exposure identified only a single example where the virus was known to have
spread during an outdoor contact. It is entirely possible that the lack of evidence of weather effects on the spread of COVID-19 reported above is
primarily due to indoor spread under conditions that may be decoupled from the ambient weather.
Under these circumstances, it appears likely that COVID-19 will remain capable of significant spread during warm and sunny conditions, as already
evidenced by the serious outbreaks in locations such as Ecuador and Brazil.
|
