Project description

* This project contains an infographic (project link) and an interactive version (additional link).

The summer of 2018 was possibly the hottest season in Japan’s history. The average temperature in June – August was the highest since records had begun in 1946. In statistics, there is no room for doubt that Tokyo is getting hotter. So how did this happen?

This infographic shows the average daily temperature during the summer season (June to September) in Tokyo over the course of 140 years. The cells indicate the average temperature in the day by 2°, from blue (less than 18°C) to deep red (30°C or more). This heat map clearly indicates that the temperature in Tokyo has been rising steadily and is now approaching dangerous levels. We can also see that summers are becoming longer than before. Even September, which was considered to be the beginning of autumn in the past, has included days with temperatures of over 30°C in recent years.

What makes this project innovative?

Since temperature dataset is large in volume and complicated in structure, it is difficult to express in a basic chart. Although people have inferred that summer is hot compared to the past, they have not been certain of it. What makes this project innovative is that this infographic provides clear, visual evidence of temperature change. By making a visual display of changes that cannot be expressed in basic charts, the infographic strongly support people's intuition.

What was the impact of your project? How did you measure it?

This article has become one of the most shared in our media. Taking both the visual and the explanation page together, it has been read by over 260,000 users (unique browsers), shared 6.8 thousand times on Facebook and 14.3 thousand times on Twitter. Various people such as politicians, scientists and designers have commented on these data, including being adopted as one of the subjects of a university entrance exam question. In addition, since we have published the data that we scraped and formatted, engineers and researchers have visualized them in their own ways. The data have been used for various reasons, such as by those who have verified them against data sources and those who have used them to create their own, similar visuals.

Source and methodology

We retrieved the data from the Japan Meteorological Agency, which publishes meteorological data such as the daily average temperature or weather. We scraped the data by using PHP, stored them to MySQL database and formatted them into a JSON file. P5.js, an JavaScript alternative of Processing, was used to create infographic.

Technologies Used

P5.js to generate images / PHP to scrape web pages / MySQL to store and format data into a JSON file / HTML, CSS, JavaScript to draw an interactive page

Project members



Additional links


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