Twain is a census-designated place (CDP) in Plumas County, California, United States. As of the 2020 census, the CDP population was 75, down from 82 at the 2010 census.
Twain is located at (40.018101, -121.048898).
According to the United States Census Bureau, the CDP has a total area of , all of it land.
This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 ðF. According to the Köppen Climate Classification system, Twain has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps.
Twain first appeared as a census designated place in the 2000 U.S. census.
The 2020 United States census reported that Twain had a population of 75. The population density was . The racial makeup of Twain was 64 (85%) White, 0 (0%) African American, 5 (7%) Native American, 1 (1%) Asian, 0 (0%) Pacific Islander, 3 (4%) from other races, and 2 (3%) from two or more races. Hispanic or Latino of any race were 4 persons (5%).
There were 32 households, out of which 5 (16%) had children under the age of 18 living in them, 9 (28%) were married-couple households, 6 (19%) were cohabiting couple households, 6 (19%) had a female householder with no partner present, and 11 (34%) had a male householder with no partner present. 12 households (38%) were one person, and 10 (31%) were one person aged 65 or older. The average household size was 2.34. There were 14 families (44% of all households).
The age distribution was 10 people (13%) under the age of 18, 4 people (5%) aged 18 to 24, 8 people (11%) aged 25 to 44, 21 people (28%) aged 45 to 64, and 32 people (43%) who were 65years of age or older. The median age was 62.2years. There were 31 males and 44 females.
There were 43 housing units at an average density of , of which 32 (74%) were occupied. Of these, 12 were owner-occupied and 20 were occupied by renters.
At the 2000 census, the median household income was $16,071 and the median family income was $10,313. The per capita income for the CDP was $19,472. There were 70.6% of families and 72.1% of the population living below the poverty line, including no under eighteens and 100.0% of those over 64.
In the state legislature, Twain is in , and .
Federally, Twain is in .
The school district is Plumas Unified School District.