[3] Clearlake is 4.5 miles (7.2 km) north-northwest of Lower Lake,[4] at an elevation of 1,417 feet (432 m).

[clarification needed] The first inhabitants of Clearlake were the Pomo Indians, who named many of the area's features, including Mount Konocti.

Beginning in 1821, enslavement and mistreatment by Spanish soldiers and missionaries, Mexican land barons, European settlers, and gold diggers, combined with a lack of natural immunity to European diseases, resulted in a massive wave of deaths.

The result of this was massive amounts of land freed up for the white settlers who arrived during the gold rush.

Clearlake has a hot-summer Mediterranean climate (Köppen: Csa) with hot, dry summers and cool, wet winters.

There were 8,035 housing units at an average density of 759.4 per square mile (293.2/km2), of which 3,190 (39.7) were owner-occupied, 2,780 (34.6%) were occupied by renters and 2065 (25.7%) were vacant.

At the 2000 census there were 13,142 people in 5,532 households, including 3,313 families, in the city.

Out of the total population, 39.8% of those under the age of 18 and 8.4% of those 65 and older were living below the poverty line.

In the state legislature, Clearlake is in the 2nd Senate District, represented by Democrat Mike McGuire,[12] and in the 4th Assembly District, represented by Democrat Cecilia Aguiar-Curry.

[13] Federally, Clearlake is in California's 4th congressional district, represented by Democrat Mike Thompson.