Also, compare the conditions of even many rural sites between 50 years ago and today. At most rural measurements sites, the population density (and hence, dissipation from homes) has gone up. Also, at such sites, dissipation from increased numbers of power lines and increased units of outdoor mounted electronics, lighting and even excitation of the water vapor in the air by greater and greater densities of RF and microwave energy (got cell phone?) have to increase average surface and near surface temperatures. The weather services of the US and other countries simply could not afford, under any circumstances, to maintain a vast array of weather stations miles and miles from the nearest roads, homes, utility poles and cell phone base stations.
Several years ago the late John Daly did an extensive review of the errors in the surface record and he concluded that the weather stations that had been best maintained show little or no warming at all. The satellite record, which is confirmed by balloon soundings, bears this out.