Walnut is located in south California. Walnut is part of Los Angeles County. Walnut has 8.99 square miles of land area and 0.00 square miles of water area. As of 2010-2014, the total Walnut population is 29,822, which has shrunk 0.61% since 2000. The population growth rate is much lower than the state average rate of 12.39% and is much lower than the national average rate of 11.61%. Walnut median household income is $100,934 in 2010-2014 and has grown by 24.59% since 2000. The income growth rate is lower than the state average rate of 29.47% and is lower than the national average rate of 27.36%. Walnut median house value is $635,000 in 2010-2014 and has grown by 127.03% since 2000. The house value growth rate is much higher than the state average rate of 75.60% and is much higher than the national average rate of 46.91%. As a reference, the national Consumer Price Index (CPI) inflation rate for the same period is 26.63%. On average, the public school district that covers Walnut is much better than the state average in quality. The Walnut area codes are 909, 951.