Historical temperature data comes in different formats. Such as maps, graphs, documented research, and sometimes opinions which at times tend to leave out documented research. There are sites to numeruos to mention on the internet when it comes to looking up historical temperature data etc. But a good place to Climate Data is NOAA's National Climatic Data Center.
The link at the bottom of the page will present an objective view of Global Climate Change, Historic Temperatures, Winter Climate, etc.. if they are looking for research material or are just curious about our past climate.
This data is primarily intended for the study of climate variability and weather change. Whenever possible, observations have been adjusted to account for the artificial effects introduced into the climate record by factors such as instrument changes, station relocations, observer practice changes and urbanization. As a result, some values available on this site differ from the official observations.
This site will be a good starting point if you intend to set up your own Weather Almanac or your just looking for more information on Global Climate Change. I hope you enjoy my Weather site.