2020 census As of the
2020 census, Shasta Lake had a population of 10,371 and a population density of . The median age was 41.4 years. The age distribution was 22.4% under the age of 18, 6.8% aged 18 to 24, 25.1% aged 25 to 44, 26.5% aged 45 to 64, and 19.2% aged 65 or older. For every 100 females, there were 98.1 males, and for every 100 females age 18 and over, there were 94.5 males age 18 and over. The census reported that 99.8% of the population lived in households, 0.2% lived in non-institutionalized group quarters, and no one was institutionalized. In addition, 90.7% of residents lived in urban areas, while 9.3% lived in rural areas. There were 4,091 households, out of which 31.1% had children under the age of 18 living in them. Of all households, 43.5% were married-couple households, 9.4% were
cohabiting couple households, 27.9% had a female householder with no spouse or partner present, and 19.2% had a male householder with no spouse or partner present. About 25.5% of all households were made up of individuals, and 12.8% had someone living alone who was 65 years of age or older. The average household size was 2.53, and there were 2,697 families (65.9% of all households). There were 4,373 housing units at an average density of , of which 4,091 (93.6%) were occupied. Of occupied units, 70.3% were owner-occupied and 29.7% were occupied by renters. 6.4% of housing units were vacant. The homeowner vacancy rate was 1.9%, and the rental vacancy rate was 2.4%.
2010 census The
2010 United States census reported that Shasta Lake had a population of 10,164. The population density was . The
racial makeup of Shasta Lake was 8,749 (86.1%) White, 67 (0.7%) African American, 389 (3.8%) Native American, 233 (2.3%) Asian, 13 (0.1%) Pacific Islander, 201 (2.0%) from
other races, and 512 (5.0%) from two or more races. Hispanic or Latino of any race were 865 persons (8.5%). The Census reported that 10,147 people (99.8% of the population) lived in households, 17 (0.2%) lived in non-institutionalized group quarters, and 0 (0%) were institutionalized. There were 3,943 households, out of which 1,325 (33.6%) had children under the age of 18 living in them, 1,830 (46.4%) were
opposite-sex married couples living together, 566 (14.4%) had a female householder with no husband present, 280 (7.1%) had a male householder with no wife present. There were 342 (8.7%)
unmarried opposite-sex partnerships, and 33 (0.8%)
same-sex married couples or partnerships. 961 households (24.4%) were made up of individuals, and 413 (10.5%) had someone living alone who was 65 years of age or older. The average household size was 2.57. There were 2,676
families (67.9% of all households); the average family size was 3.00. The population was spread out, with 2,467 people (24.3%) under the age of 18, 844 people (8.3%) aged 18 to 24, 2,511 people (24.7%) aged 25 to 44, 2,877 people (28.3%) aged 45 to 64, and 1,465 people (14.4%) who were 65 years of age or older. The median age was 38.8 years. For every 100 females, there were 99.5 males. For every 100 females age 18 and over, there were 95.9 males. There were 4,209 housing units at an average density of , of which 2,623 (66.5%) were owner-occupied, and 1,320 (33.5%) were occupied by renters. The homeowner vacancy rate was 2.0%; the rental vacancy rate was 5.2%. 6,588 people (64.8% of the population) lived in owner-occupied housing units and 3,559 people (35.0%) lived in rental housing units. ==Schooling==