According to the United States Census Bureau, the town has a total area of , all of it land. The town is located on the north side of the South Platte River, along U.S. 138 and U.S. 385 and just off of I-76. It is the northernmost town in the state, less than south of the Colorado−Nebraska state line. Julesburg experiences a semi-arid climate (Köppen "BSk") with cold, dry winters and hot, wetter summers. As of the census of 2000, there were 1,467 people, 613 households, and 407 families residing in the town. The population density was 1,167.6 people per square mile (449.5/km²). There were 699 housing units at an average density of 556.4 per square mile (214.2/km²). The racial makeup of the town was 89.03% White, 0.20% African American, 0.07% Native American, 0.41% Asian, 0.14% Pacific Islander, 7.77% from other races, and 2.39% from two or more races. Hispanic or Latino of any race were 14.18% of the population. There were 613 households out of which 28.2% had children under the age of 18 living with them, 54.8% were married couples living together, 7.3% had a female householder with no husband present, and 33.6% were non-families. 31.2% of all households were made up of individuals and 14.2% had someone living alone who was 65 years of age or older. The average household size was 2.30 and the average family size was 2.86. In the town, the population was spread out with 23.4% under the age of 18, 7.2% from 18 to 24, 23.9% from 25 to 44, 21.2% from 45 to 64, and 24.4% who were 65 years of age or older. The median age was 42 years. For every 100 females, there were 90.3 males. For every 100 females age 18 and over, there were 90.5 males. The median income for a household in the town was $28,207, and the median income for a family was $34,500. Males had a median income of $27,337 versus $17,125 for females. The per capita income for the town was $14,913.