The issue with this piece of work is that the author hasn't even attempted to think of reasons for results he/she plotted. Simply presenting provocative data without adequate attempts to explain the results is irresponsible. People will take this data and say, "See global warming isn't happening!" but that is not the right takeaway.
One possible explanation for the data is that, regardless of whether or not the Earth is getting warmer, cooler, or staying the same temperature, you would always expect some places to be getting warmer over a given time period, some places to get colder, and some places to stay the same. That's just a property of a random system. Without sampling enough points, you can't say how the global temperature is changing because you don't have enough data. Another issue is that the author largely chooses cities. It may be that cities are more likely to be built in an area if that area has a stable climate. As other have mentioned, even a 1 degree change is temp is significant, so the scale of the graphs is wrong too.
A good illustration of how random systems can do weird things is this wealth simulator: https://www.masswerk.at/misc/wealth/
In this simulator, 55 "participants" are given $45 and at each step in the simulation, each participant randomly gives another participant $1. Even though all of the action in this simulation is random, some participants typically acquire much more wealth than others. If you sampled random participants after N steps, some would gain money, and others would lose money. Rarely would the wealth of a participant stay the same. If you didn't understand the rules of the simulation, and were only presented with the data, you'd need to analyze data from all of the participants to conclude that total wealth had stayed constant.