Above is a Histogram for weather stations in Europe. It shows the data (temperature) frequency and variations across the different stations. This graph also makes it easy to spot outliers. As you can see, the majority of the data is in the 2.72-3.34 range. It follows a bell curve for the most part, with an outlier on the upper end of the spectrum.
This was created in ArcMap, using the Histogram tool in the Geostatistical Analyst toolbar.