The county has a humid continental climate (Dfa/Dfb). Average temperatures in Sunbury range from 27.3 °F in January to 72.7 °F in July, while in Mount Carmel they range from 25.0 °F in January to 70.2 °F in July.
The county has a humid continental climate (Dfa/Dfb) Average temperatures in Sunbury range from 273 °F in January to 727 °F in July while in Mount Carmel they range from 250 °F in January to 702 °F in July