The upper part of the county's western boundary is formed by the outline of Lac qui Parle reservoir, which was formed when the Minnesota River was dammed in 1939. The Minnesota River flows southeast from the lake, along the county's southwestern border, while the Chippewa River flows south through the western part of the county to discharge into the Minnesota at the county's southern border. The Dry Weather Creek drains the west-central part of the county into the Chippewa, while the Palmer Creek drains the lower central part of the county into the Minnesota near the county's southernmost point. The county terrain consists of low rolling hills, devoted to agriculture. The terrain generally slopes to the south, and locally to the river valleys. The county's highest point is at its NE corner, at 1,109' ASL. The county has a total area of, of which is land and is water.
In recent years, average temperatures in the county seat of Montevideo have ranged from a low of in January to a high of in July, although a record low of was recorded in January 1970 and a record high of was recorded in July 1988. Average monthly precipitation ranged from in December to in June.
Demographics
2000 census
As of the 2000 United States Census, there were 13,088 people, 5,361 households, and 3,597 families in the county. The population density was 22.5/sqmi. There were 5,855 housing units at an average density of 10.1/sqmi. The racial makeup of the county was 96.78% White, 0.18% Black or African American, 1.00% Native American, 0.30% Asian, 0.02% Pacific Islander, 0.94% from other races, and 0.79% from two or more races. 1.92% of the population were Hispanic or Latino of any race. 37.8% were of Norwegian and 36.8% German ancestry. There were 5,361 households, out of which 31.20% had children under the age of 18 living with them, 57.00% were married couples living together, 6.60% had a female householder with no husband present, and 32.90% were non-families. 29.50% of all households were made up of individuals and 15.70% had someone living alone who was 65 years of age or older. The average household size was 2.39 and the average family size was 2.96. The county population contained 25.40% under the age of 18, 7.10% from 18 to 24, 24.50% from 25 to 44, 23.00% from 45 to 64, and 20.00% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 94.80 males. For every 100 females age 18 and over, there were 91.30 males. The median income for a household in the county was $35,582, and the median income for a family was $45,160. Males had a median income of $30,556 versus $20,384 for females. The per capita income for the county was $18,039. About 4.80% of families and 8.60% of the population were below the poverty line, including 9.80% of those under age 18 and 9.30% of those age 65 or over.
Chippewa County voters have tended to vote Democratic in recent decades. As of 2016 the county has selected the Democratic presidential candidate in 67% of national elections since 1980.
