It is bordered to the southwest by Interstate 89 and extends north along the highway to Exit 9 (New Hampshire Route 103).

The northern edge of the CDP is north of Split Rock Road and Kirtland Street, and the eastern extent is at Willow Brook, a tributary of the Warner River.

According to the U.S. Census Bureau, the Warner CDP has a total area of 0.81 square miles (2.1 km2), all of it recorded as land.

[4] As of the census of 2010, there were 444 people, 204 households, and 118 families residing in the CDP.

36.8% of all households were made up of individuals, and 22.6% were someone living alone who was 65 years of age or older.