Source adapted from: Selected Maps from the Climate Office of the United States | NOAA
The Growing Season refers to the number of days between the date of the last frost in the spring, which ranges from April 1st - June 1st, and the first frost of the autumn, from Sept 1st- Oct 31st. The growing season in the Pennsylvania Lowlands is typically 6 to 7 months long, because of the warm summers and mild winters. Because of the severe winters and mild summers, the growing season in the Uplands averages only 130 days.