When will flu season end?

(NEXSTAR) – With all the people coughing, sneezing and calling out sick around you, it's probably pretty clear we're in the thick of flu season.

Flu activity remains "very high" in most states, the Centers for Disease Control said this week, as illnesses, emergency room visits and hospitalizations all continue to trend upward.

That will eventually change, and peak flu season will end, but it's difficult to predict exactly when. That's because there is no precise start and end of flu season. Diseases don't respect calendar date cut-offs. That being said, most cases of influenza occur between October and May.

Flu activity typically peaks before we get late into spring. According to the CDC, the most common time for influenza to reach its peak in the U.S. is February (which explains the feeling that everyone seems to be sick right now).

The peak can also come sooner or later. The second-most common month for flu activity to reach its height is December. January and March are tied for third.

Flu activity typically tapers off as we move out of winter and into spring, but the virus is still detected year-round.

This year, flu activity appears to be returning to pre-pandemic levels. Dr. Amesh Adalja, an infectious disease expert at Johns Hopkins Center for Health Security, said that can give us the illusion that it's an especially bad season.

“I think a lot of people have been acclimatized to relatively mild flu seasons the last several years, because the COVID-19 pandemic really disrupted the circulation of flu,” Adalja told Nexstar. “This season has been more on par with with seasons that we saw pre-COVID. It’s sort of going back to resembling what we used to have in 2018-19, which people have long forgotten about.”

While experts say the best time to get vaccinated against influenza is in the fall, it's not too late. The flu vaccine can still offer protection against getting sick and severe illness.