Flu seasons have been particularly bad in recent years and this one in no different.

An estimated 6.2 million to 7.3 million people in the United States have been sick with the flu since October, federal health officials said Friday. At least half of those people have sought medical care for their illness and 69,000 to 84,000 people have been hospitalized during the Oct. 1 to Jan. 5 period, the Centers for Disease Control and Prevention estimated.

This is the first time the CDC has provided such flu estimates for the 2018-2019 season. The estimates are extrapolated from data from about 27 million people, or about 8.5 percent of the U.S. population, federal health officials said.

While the numbers are milder than last season, the CDC's "influenza like illness level" last week was elevated at 4.1 percent, almost twice national baseline. There were widespread flu outbreaks across 31 states, including New York, California and Florida, last week, the CDC said. It was widespread throughout almost every state during the same period last year.

The CDC hasn't released data on the total number of deaths so far this season, saying 16 influenza-associated pediatric deaths have been reported to the agency this season. Reports of flu-related mortality are starting to come in across the country. The Oklahoma State Department of Health has attributed 13 deaths there to the flu since Sept. 1, two of them since the new year.

The City of El Paso Department of Public Health confirmed its first flu-related death Monday, a man in his 80s with other medical issues who hadn't been vaccinated. The New Jersey Department of Health confirmed Tuesday that a child died of the flu, the first of the season, and said there were high levels of flu throughout the state.

The flu season typically runs from October to as late as May, with activity tending to peak between December and February, according to the CDC. The agency recommends getting vaccinated early, ideally by the end of October, before the flu starts spreading.

Babies older than 6 months should get vaccinated with a traditional shot. For toddlers age 2 or older a shot or a nasal spray called FluMist is recommended.

The CDC also recommends that people with a flu-like illness should stay home for at least 24 hours after the fever is gone except to get medical care or for other necessities.

Thirty-seven percent of U.S. adults were estimated to have been vaccinated last flu season, down 6 percentage points from the previous year, according to the CDC. It estimates that the flu killed more than 80,000 people and caused more than 900,000 hospitalizations last year.

—CNBC's Angelica LaVito contributed to this report.