Both NASA and the World Meteorological Organization both have excellent posts I'm going to excerpt at length. The first, from NASA's Goddard Institute for Space Studies website, is titled
July 2010 — What Global Warming Looks Like
The July 2010 global map of surface temperature anomalies (Figure 1), relative to the average July in the 1951-1980 period of climatology, provides a useful picture of current climate. It was more than 5°C (about 10°F) warmer than climatology in the eastern...