Bloomberg's late-stage infusion of cash reflects Democrats' concerns about the tight race in a state that is a priority for President Donald Trump.
The spending revelation from the former mayor of New York City comes as Trump's significant funding advantage over Biden has dried up amid reports of free-spending early on in the campaign.
"Mike Bloomberg is committed to helping defeat Trump, and that is going to happen in the battleground states", said Bloomberg adviser Kevin Sheekey, who added that the spending "will mean Democrats and the Biden campaign can invest even more heavily in other key states like Pennsylvania, which will be critical to a Biden victory". It will be the biggest prize among competitive states on Election Day, offering 29 of the 270 Electoral College votes needed to win.
The Bloomberg spokesperson noted that Florida starts voting on September 24.
Mr Trump narrowly lost Nevada in 2016 to Mrs Clinton, and the state has trended further toward the Democrats in the past decade. Once considered fairly safely in Trump's column, Arizona has been ravaged by the coronavirus and the Trump team has grown anxious about a slip in support among the state's older residents. State Republicans blamed Democratic Gov. Steve Sisolak for trying to hurt the president's reelection chances, even though the Reno rally was canceled by airport officials and Las Vegas airport officials said they were never contacted by the campaign.
Nationally, little public polling is available to measure the opinions of Latino voters this year and whether they differ from four years ago.
One of the world's wealthiest men with a net worth estimated to exceed US$60 billion, Bloomberg promised throughout his campaign that he would help Democrats try to defeat Trump regardless of how his own White House bid fared.
Earlier this week when asked by journalists if he was considering spending his own money in Florida, Mr Trump told reporters "If I have to, I will". Though the Trump campaign has insisted that it has more resources on hand than it did at this time in 2016, whispers about a financial disadvantage led Trump himself this past week to suggest he may put some of his own fortune into the race.
Biden has hammered Trump for failing to lay out a national strategy to combat the pandemic, which has killed more than 193,000 people in the United States.
President Donald Trump has signed a new executive order on prescription drugs, which he said will force the makers of pharmaceuticals to give U.S. consumers the same lower prices that they charge in Canada and other countries.
Democrats had anxious that Bloomberg's promised help for the party might not come through after he abandoned his own presidential primary campaign.
Mr Bloomberg endorsed Mr Biden after failing to win the Democratic nomination and spoke in a prime-time slot at the Democratic convention in August. A Bloomberg adviser said much of the money will go to television and digital advertising.