"Local" warming in California

Here.

Excerpt:

The three researchers found that "most regions showed a stronger increase in minimum temperatures than with mean and maximum temperatures," and that "areas of intensive urbanization showed the largest positive trends, while rural, non-agricultural regions showed the least warming." In fact, they report that the Northeast Interior Basins of the state actually experienced cooling. Large urban sites, on the other hand, exhibited rates of warming "over twice those for the state, for the mean maximum temperatures, and over five times the state's mean rate for the minimum temperature."

From the comment section:

Not only is it blindingly obvious that the Urban Heat Island effect is responsible for recording higher minimum temperatures, it is also responsible for many weather stations that were previously well sited to become mini-urban heat islands as parking lots and buildings and air-conditioners encroach on those sites and significantly skew the temperatures being recorded... both higher lows and higher highs... and, presto, global warming!