There was also a corresponding decrease in the rate of deaths (mortality) from the disease, with a roughly 15% drop in mortality for every one degree Celsius rise in temperature. By contrast, the severity of symptoms and mortality rate remained constant in China during the first wave of the pandemic, which occurred solely throughout the winter.
These changes were too large to be explained by improvements in treatment of COVID-19, patient age or hospitals becoming overwhelmed during this time, suggesting that there is a seasonal influence on the virus.
It gets complicated when it’s hot enough to require air conditioning and people live in a society where you just move from one air conditioned bubble to another.
Brace yourself, winter is coming:
https://www.medrxiv.org/content/10.1101/2020.07.11.20147157v2