The county is part of the North Central Pennsylvania region of the state.

[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.

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.

Under Pennsylvania law, there are four types of incorporated municipalities: cities, boroughs, townships, and, in at most two cases, towns.