It never has been just a winter virus, its still wave after wave and doesn’t seem particularly interested in a pattern. There has for a few years been a vague summer and winter pattern but then this year its mostly just hit a wave in Autumn. Its still doing its pandemic thing with new variants, immune waning and events being the driving force of new waves.

People are just inside more and closer together in the winter. Since work places don’t want people staying home when sick, and most people are too big of assholes to wear a mask when sick, it spreads