According to the U.S. Census Bureau, the county has a total area of 657 square miles (1,700 km2), of which 652 square miles (1,690 km2) is land and 4.4 square miles (11 km2) (0.7%) is water.[5] It has a warm-summer humid continental climate (Dfb) and average monthly temperatures in Brookville range from 24.8 °F in January to 68.8 °F in July, while in Punxsutawney they range from 25.7 °F in January to 69.6 °F in July.[6] Jefferson County is one of the 423 counties served by the Appalachian Regional Commission,[7] and it is identified as part of the "Midlands" by Colin Woodard in his book American Nations: A History of the Eleven Rival Regional Cultures of North America.[8]
There are many named streams flowing through Jefferson County, far too many to list here. An exhaustive list is presented in a separate article. All those streams eventually flow to the Allegheny River except for Bear Run, 1.36 square miles (3.5 km2), in the southeast which flows into the Susquehanna River. The principal streams and the area of their watersheds that lie within the county are:
As of the census[10] of 2000, there were 45,932 people, 18,375 households, and 12,862 families residing in the county. The population density was 70 people per square mile (27 people/km2). There were 22,104 housing units at an average density of 34 units per square mile (13/km2). The racial makeup of the county was 98.97% White, 0.13% Black or African American, 0.16% Native American, 0.21% Asian, 0.01% Pacific Islander, 0.07% from other races, and 0.45% from two or more races. 0.41% of the population were Hispanic or Latino of any race. 31.1% were of German, 13.4% Italian, 10.8% American, 9.2% Irish and 7.8% English ancestry.
There were 18,375 households, out of which 30.30% had children under the age of 18 living with them, 56.80% were married couples living together, 9.10% had a female householder with no husband present, and 30.00% were non-families. 26.60% of all households were made up of individuals, and 13.80% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 2.96.
In the county, the population was spread out, with 23.60% under the age of 18, 7.70% from 18 to 24, 27.20% from 25 to 44, 23.60% from 45 to 64, and 17.90% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 95.70 males. For every 100 females age 18 and over, there were 92.60 males.
The Jefferson County Fair is held annually in July.
Communities
Map of Jefferson County, Pennsylvania with Municipal Labels showing Boroughs (red) and Townships (white).
Under Pennsylvania law, there are four types of incorporated municipalities: cities, boroughs, townships, and, in at most two cases, towns. The following boroughs and townships are located in Jefferson County:
^Center, Legislativate Data Processing. "Find Your Legislator". The official website for the Pennsylvania General Assembly. Archived from the original on May 6, 2017. Retrieved May 11, 2017.
