Why do covid cases rise in summer, unlike other respiratory viruses?

Flu and other respiratory viruses seem to barely exist outside of winter, but covid-19 cases have consistently risen every summer over the past few years

​Flu and other respiratory viruses seem to barely exist outside of winter, but covid-19 cases have consistently risen every summer over the past few years Flu and other respiratory viruses seem to barely exist outside of winter, but covid-19 cases have consistently risen every summer over the past few years