Fall is the time of year people start to fall for more of what the
corporate/government/healthcare/media entities and other
authoritative sources tell them about the coronavirus. At least in the spring and summer, people are outside around other people for more of the day, and they can see that other people are doing fine. In fall and winter, people don't have that added sense of security, and
the corporate/government/health/media entities and other
authoritative sources take advantage of that unease.