Multiple major sports championship seasons

In the history of North American major professional sports league championships (which include the NFL, MLB, NBA, and NHL) a city/metropolitan area has been home to multiple championships in a season eighteen times, most recently in 2020–2021 when the Tampa Bay Lightning and Tampa Bay Buccaneers won their respective championships. 
Philadelphia is the only city to have all four major sports teams (MLB's Phillies, NBA's 76ers, NFL's Eagles, and NHL's Flyers) play in their respective championship game or series in the same season (in 1980), though only one of the four (Phillies) actually won the championship. The Tampa Bay area, which does not have an NBA team, had all three of its major sports teams (MLB's Rays, NFL's Buccaneers, and NHL's Lightning) play in their respective championships in the 2020 season, with the Lightning and Buccaneers winning the championships. 
Definitions.
Because some of the present-day "big four" North American sports leagues have merged with other leagues and their championships in the past, this article considers the following to be major sports championships:
Teams which are based in the same metropolitan area are considered together for this article even if they are not based in the same city. For example, teams representing Oakland, California are grouped with other teams based in the San Francisco Bay Area, while teams playing in or representing New Jersey are grouped with other teams based in the New York City metropolitan area.
While the Super Bowl game is held in February (January prior to 2002), a Super Bowl championship is considered to be the championship for the year in which the regular season was played; for example, Super Bowl LIII, played on February 3, 2019, was the championship game for the 2018 NFL season and is thus considered a 2018 championship. All other championships including pre-Super Bowl football championships are considered to have been won the year in which the championship was awarded.