In the hot summer, you're more likely to order iced coffee than hot coffee at a coffee shop.
Iced coffee is likely to sell better than hot coffee in the summer for coffee shops as well.
There are two types of iced coffee: the gold brew method, which uses water to extract the coffee over a long period of time, and the rapid-chill method, which involves quickly cooling hot coffee at around 90 degrees Celsius with ice to make it iced. In Japan, the rapid-chill method is the most common.