The weather is warming up, flowers are starting to bloom, and flu season is over -- right? As it turns out, Americans are still getting the flu.

The Centers for Disease Control and Prevention says this year's flu season has been one of the longest since 1997, when it started keeping records. And it is the longest in the past decade.

"This year was the longest flu season we've seen in the past 10 years," said Lynnette Brammer of the CDC Influenza Division, CBS New York reported. "Previously the longest was 20 weeks and right now we're at 21."

Get Breaking News Delivered to Your Inbox

One reason for the long flu season is that two types of flu viruses surfaced at different times.

"The beginning of the season was H1N1 predominant, and then as that went down, H3N2 viruses went up," said Brammer. "We did have two different waves of influenza this year."

"I don't remember a season like this," said Dr. Arnold Monto, a University of Michigan researcher, The Associated Press reported.

So far this season, up to 41.3 million people showed flu symptoms, with up to 19.4 million visiting the doctor and as many as 610,000 hospitalized.

While flu cases are declining, doctors say the virus can still spread even in the warmer weather.

"Given the way the flu season is going, if you have flu-like symptoms, there's a good chance you do have flu," said Brammer.

An important reminder is to take common-sense precautions like washing hands and staying home when sick to prevent spreading the virus.