The average temperature in Charlotte the average temperature is 34.47 degrees in summer, with precipitation around 12.0 mm , Waterloo, IA's temperatures reach 33.73 during the hot season, with 9.0 average of rain rate . In winter, however, weather indicators show around -22.76 degrees in Waterloo, IA, compared to the -6.78 average degrees reported in Charlotte. During the winter period, Charlotte can register 9.0 mm precipitation, while Waterloo, IA have an average of 3.0 mm rain level.