Seffner's post office was opened in 1884, after the existence of the new railroad was a certainty. Actually, the community had existed at least for several years as "Lenna City", while the railroad was being built. The community is named for its first postmaster, F.P. Seffner. Seffner, Mango and Dover were the three principal towns along the South Florida Railroad right-of-way between Tampa and Plant City. They owe their existence and prosperity to the railroad. Each became an important shipping center and Seffner was the fourth largest town in the county by 1925. Located close to Tampa Bay with a population of 37,000 and 2,095 families, this community is rich in history and community appeal. Seffner is a Semi-tropical area in Florida. With an average temperature of 81 in the summer and 62 in the winter and an avarage annual rainfall of 47 inches per year, residents are sure to enjoy beautiful days year round.