The mean annual precipitation for Larrys Creek is . According to the Pennsylvania Fish and Boat Commission: "Pennsylvania receives the most acid deposition of any state in the nation because, in addition to being the third highest producer of the gases that cause acid deposition, we are also located downwind from the highest concentration of air pollution emitters." The region's geology gives it a relatively low capacity to neutralize added acid. This makes the creek especially vulnerable to increased acidification from rain, which poses a threat to the long term health of the plants and animals in the creek.