Now you see why the CRU and IPCC limited the number of stations they were using and restricted them to mostly urban stations to get the result they wanted

How They Distort Global Temperatures: The Urban Heat Island Effect

By Dr. Tim Ball
Monday, March 1, 2010

How much do calculations of global temperatures represent the real temperature of the Earth? Every day new stories appear about temperature records with errors or deliberate omissions. An important part of the debate is something called the Urban Heat Island Effect (UHIE). A new article by Dr. Edward Long says, ... ture-data/ “The problem would seem to be the methodologies engendered in treatment for a mix of urban and rural locations; that the ‘adjustment’ protocol appears to accent to a warming effect rather than eliminate it. This, if correct, leaves serious doubt for whether the rate of increase in temperature found from the adjusted data is due to natural warming trends or warming because of another reason, such as erroneous consideration of the effects of urban warming.