Warming up in California

"Average temperatures in California rose nearly two degrees Fahrenheit during the second half of the 20th
century, with urban areas blazing the way to warmer conditions. When
scientists at NASA and California State University, Los Angeles,
analyzed observations from 331 weather stations between 1950 and 2000,
they found that average temperatures rose in 6 out of 7 of the state’s
major climatic sub-regions. The scientists concluded that small
increases measured in many rural areas may reflect the contribution of
global warming due to rising greenhouse gas concentrations. Larger
changes in and around urban areas are mostly due to growing population
and the conversion of natural areas to urban ones."