Tokyo is one of the world's biggest cities. with around 13 million people, it has an area of more than 2,000 square kilometers. Most of this area is Concret buildings and streets. That's a lot of concrete.
All this concrete isn't very nice to look at. But it also makes the city hotter. The concrete in the buildings and streets absorbs a lot of heat from the sun. Scientists say that cities can be 5 degrees hotter than the countryside around them.