he weather is cooling down ever so slightly, but things are hot in concert venues around the South Florida area with two heavy-duty Livenation shows announced Tuesday. Usher heads to AmericanAirlines Arena Dec. 13.Tickets go on sale 10 a.m. Sept. 15. Usher’s announcement of a 27-city tour comes after the release of the hip-hop superstar’s new single/video She Came To Give It To You. Usher also was named the No. 1 Hot 100 artist of the 2000s decade, and was named by Billboard as the second most successful artist of the 2000s. Usher’s fellow coach on The Voice, Adam Levine, is bringing his Maroon 5 tour to the BB&T Center on Feb. 24; tickets for that concert go on sale at 10 a.m. Sept. 13. The newlywed and his band’s 27-stop North American tour follows the release last week of Maroon 5’s fifth studio album, V. Maroon 5’s previous hits include This Love, She Will Be Loved and Moves Like Jagger.