Ogallala has a dry humid continental climate, bordering on cold semi-arid with an annual average precipitation of. Winters are cold, while summers are hot and often stormy. Precipitation is greatest in the late spring and summer, with winter being the driest part of the year.
As of the census of 2010, there were 4,737 people, 2,100 households, and 1,298 families living in the city. The population density was. There were 2,397 housing units at an average density of. The racial makeup of the city was 94.6% White, 0.2% African American, 0.6% Native American, 0.4% Asian, 2.2% from other races, and 2.0% from two or more races. Hispanic or Latino of any race were 7.5% of the population. There were 2,100 households of which 27.5% had children under the age of 18 living with them, 48.0% were married couples living together, 9.6% had a female householder with no husband present, 4.2% had a male householder with no wife present, and 38.2% were non-families. 34.1% of all households were made up of individuals and 14.6% had someone living alone who was 65 years of age or older. The average household size was 2.23 and the average family size was 2.85. The median age in the city was 43.7 years. 23.6% of residents were under the age of 18; 6.8% were between the ages of 18 and 24; 21.4% were from 25 to 44; 28.3% were from 45 to 64; and 20.1% were 65 years of age or older. The gender makeup of the city was 48.8% male and 51.2% female.
2000 census
As of the census of 2000, there were 4,930 people, 2,052 households, and 1,339 families living in the city. The population density was 1,472.4 people per square mile. There were 2,314 housing units at an average density of 691.1 per square mile. The racial makeup of the city was 96.45% White, 0.02% African American, 0.87% Native American, 0.22% Asian, 1.68% from other races, and 0.75% from two or more races. Hispanic or Latino of any race were 4.79% of the population. There were 2,052 households out of which 31.5% had children under the age of 18 living with them, 53.0% were married couples living together, 9.5% had a female householder with no husband present, and 34.7% were non-families. 30.7% of all households were made up of individuals and 14.7% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.94. In the city, the population was spread out with 26.5% under the age of 18, 6.7% from 18 to 24, 26.5% from 25 to 44, 21.9% from 45 to 64, and 18.4% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 89.0 males. For every 100 females age 18 and over, there were 85.0 males. As of 2000 the median income for a household in the city was $32,141, and the median income for a family was $39,688. Males had a median income of $27,436 versus $18,292 for females. The per capita income for the city was $17,674. About 5.0% of families and 7.8% of the population were below the poverty line, including 9.3% of those under age 18 and 9.1% of those age 65 or over.
