Northumberland, PA has a humid continental climate, characterized by hot and humid summers and cold winters. The average annual temperature is approximately 51°F (11°C). Winters are usually cold and snowy with temperatures rarely dropping below zero. Summers can be quite hot and humid with temperatures frequently reaching the mid-80s (30°C). Rainfall is abundant throughout the year, averaging around 40 inches annually. Springtime brings thunderstorms which can cause flooding in some areas. Autumn brings cooler temperatures and beautiful foliage as the leaves change color. Overall, Northumberland's climate can be described as mild with all four distinct seasons.
Northumberland (zip 17857), Pennsylvania gets 42 inches of rain, on average, per year. The US average is 38 inches of rain per year.
Northumberland (zip 17857) averages 30 inches of snow per year. The US average is 28 inches of snow per year.
On average, there are 177 sunny days per year in Northumberland (zip 17857). The US average is 205 sunny days.
Northumberland (zip 17857) gets some kind of precipitation, on average, 124 days per year. Precipitation is rain, snow, sleet, or hail that falls to the ground. In order for precipitation to be counted you have to get at least .01 inches on the ground to measure.
Weather Highlights
Summer High: the July high is around 84 degrees
Winter Low: the January low is 19
Rain: averages 42 inches of rain a year
Snow: averages 30 inches of snow a year