In constant evolution, climate represents the long-term mean weather conditions of an area. The ability to determine how natural and anthropogenic influences affect the evolution of climate is not trivial. The understanding of climate requires large historical records at a multiple spatial scales that for non-specialist might be difficult to use because of the large volume of data and the lack of simple and dynamic user-friendly interfaces that integrate these data.
With the intent of allowing not only the scientist, but also the general public to interact (play) with climate models at multiple spatial and temporal scales and explore how the climate is changing through time, several groups have created easy to use internet-based tools. These tools are particularly useful for teaching, but can also help us to identify global patterns and information gaps that can have a considerable impact in the understanding of regional and local climates.
Here are links to some of those tools. I am sure that there are more. Generally each site has detailed information about where do the data come from and how they were processed.
Some illustrations can be quite shocking!