St. Petersburg is a city in Pinellas County, Florida, United States. As of the 2020 census estimate, the population was 271,842, making it the fifth-most populous city in Florida, the second-largest city in the Tampa Bay Area, after Tampa, and the largest in the state that is not a county seat (the city of Clearwater is the seat of Pinellas County). Along with Clearwater, these cities are part of the Tampa–St. Petersburg–Clearwater Metropolitan Statistical Area, the second-largest in Florida with a population of around 2.8 million. St. Petersburg is on the Pinellas peninsula between Tampa Bay and the Gulf of Mexico, and is connected to mainland Florida to the north.St. Petersburg was founded in 1888 by John C. Williams, who purchased the land, and by Peter Demens who brought the railroad industry into the area. A coin toss bet was held between Williams and Demens to name this new community. Demens won the bet and named the land after Saint Petersburg, Russia. Williams was then granted the right to name the first hotel built (which he named the Detroit Hotel). Both named their winnings after their personal hometowns. St. Petersburg was incorporated as a town on February 29, 1892 and re-incorporated as a city on June 6, 1903.Locals often refer to the city as St. Pete. Neighboring St. Pete Beach formally shortened its name in 1994 after a vote by its residents. St. Petersburg is governed by a mayor and city council.With an average of some 361 days of sunshine each year, and a Guinness World Record for logging the most consecutive days of sunshine (768 days between 1967 and 1969), it is nicknamed "The Sunshine City". Located on the Gulf of Mexico, the average water temperature is typically around 76 °F (24 °C). Due to its good weather and low cost of living, the city has long been a popular retirement destination, although in recent years the population has moved in a much more youthful direction.