Anthony Watts looks at the Santa Rosa, New Mexico, weather station. As with temperature measurements from most U.S. stations, NASA "homogenizes" (red lines) the raw data (blue lines) from Santa Rosa:
source: Watts Up With That?
Watts wryly remarks, "What was down, is now up."
Some warming skeptics say that NASA's adjustments to the historical record--seemingly based on ad hoc algorithms--account for most of the supposed post-WWII warming trend. I'm not sufficiently skilled to be certain. But given the scarcity of stories about the issue, apparently the mainstream media is.