MotorCities National Heritage Area centers on automotive history in southeast Michigan, including the factory where Henry Ford created and built the Model T, the stories behind the creation of General Motors and DamilerChrysler, and the long and sometimes tenuous relationship between labor and industry. Michigan has a temperate climate with well-defined seasons, and the warmest temperatures and longest frost-free period are found most generally in the southern part of the lower peninsula; Detroit has a normal daily mean temperature of 49°F (9°C), ranging from 23°F (–5°C) in January to 72°F (22°C) in July.