Rhinovirus. This bunch is most active in early fall, spring, and summer. They cause 10%-40% of colds. You’ll feel plenty miserable when you catch one, but the good news is they rarely make you seriously sick.
Coronavirus. These tend to do their dirty work in the winter and early spring. The coronavirus is the cause of about 20% of colds. There are more than 30 kinds, but only three or four affect people.
RSV and parainfluenza. These viruses cause 20% of colds. They sometimes lead to severe infections, like pneumonia, in young children.