The West Branch of the Susquehanna River acts as the city limits to the north, while the southern borders are determined by Bald Eagle Creek which empties into the Susquehanna two miles east of the town proper. Bald Eagle Mountain rises to an elevation of 1500 to 2000 feet one mile to the south. The climate is Humid Continental, and most weather systems that affect the area develop in the Central Plains or Midwest and are steered eastward by the prevailing westerlies aloft. The primary source of moisture is the Gulf of Mexico with an occasional contribution by the Atlantic Ocean. Due to the long overland trajectory, cold Canadian high pressure air masses are somewhat modified by the time they reach central Pennsylvania.
Summers are warm and at times humid.
Daytime highs usually reach into the mid-80s with nighttime lows in the comfortable upper 50s. Prevailing winds are from the southwest averaging 8 to 10 mph. Summer season rainfall is adequate, falling for the most part in the form of late afternoon and evening thundershowers which are observed on the average of 22 days from June through August. A rather persistent cloudiness occurs during the winter due to frequent cold frontal passages. Even while under the influence of cold high pressure, the orographic effects of the nearby mountains enhance cloud development.