|• Total||1.8 sq mi (4.6 km2)|
|• Land||0.8 sq mi (2.1 km2)|
|• Water||1.0 sq mi (2.5 km2)|
|• Density||477.6/sq mi (184.8/km2)|
|Time zone||Eastern (EST) (UTC-5)|
|• Summer (DST)||EDT (UTC-4)|
|Area code(s)||570 Exchange: 758|
Herndon, formerly Trevorton Junction, is a borough in Northumberland County, Pennsylvania, United States. Herndon was first founded by Robert A. Parrish in 1840. The town was later named for Naval commander William Lewis Herndon, who died in 1857 while trying to rescue passengers from his sinking ship. The population was 324 at the 2010 census.
Herndon is located at .(40.704241, -76.843212)
According to the United States Census Bureau, the borough has a total area of 1.8 square miles (4.7 km2), of which, 0.8 square miles (2.1 km2) of it is land and 1.0 square mile (2.6 km2) of it (55.06%) is water.
As of the census of 2000, there were 383 people, 173 households, and 106 families residing in the borough. The population density was 477.6 people per square mile (184.8/km²). There were 192 housing units at an average density of 239.4 per square mile (92.7/km²). The racial makeup of the borough was 97.91% White, 1.83% African American, and 0.26% from two or more races.
There were 173 households out of which 20.2% had children under the age of 18 living with them, 56.1% were married couples living together, 4.0% had a female householder with no husband present, and 38.2% were non-families. 34.7% of all households were made up of individuals and 18.5% had someone living alone who was 65 years of age or older. The average household size was 2.21 and the average family size was 2.83.
In the borough the population was spread out with 18.5% under the age of 18, 7.0% from 18 to 24, 27.9% from 25 to 44, 24.5% from 45 to 64, and 21.9% who were 65 years of age or older. The median age was 43 years. For every 100 females there were 84.1 males. For every 100 females age 18 and over, there were 90.2 males.
The median income for a household in the borough was $37,750, and the median income for a family was $44,063. Males had a median income of $29,875 versus $17,969 for females. The per capita income for the borough was $23,156. About 5.7% of families and 9.4% of the population were below the poverty line, including 9.1% of those under age 18 and 22.1% of those age 65 or over.
Herndon is served by Line Mountain Jr./Sr. High School.