Pennsylvania is entirely within the continental climate zone, but the climate varies by area and altitude. The state experiences four seasons, which can vary based on location. Summer is hot, humid and long, particularly in the southeast. The mountainous areas are cooler and somewhat less humid. Autumn is moderate, while winter is cold and snowy. The temperatures in the area around Lake Erie are generally cooler.
Generally, the hottest month of the year in Pennsylvania is July, and the coldest is January. The state has an average temperature of 55.85 degrees Fahrenheit, with an average annual high temperature of 64.7 degrees Fahrenheit and an average annual low temperature of 47 degrees Fahrenheit. Temperatures can reach over 90 degrees Fahrenheit in the southeast and southwest areas in the hotter months. In January, the temperature can drop down to 23 degrees Fahrenheit. The state gets an average of 41.45 inches of rainfall per year and an average of 23 inches of snowfall per year. The snowfall near Lake Eire, which is in the snow belt, can exceed 54 inches per year, and heavy snows sometimes continue into April. Pennsylvania has experienced several destructive floods, such as the floods in 1889, 1972 and 1977, which caused much death and destruction. Tornadoes may also hit the area.