The Environment Ministry is creating its first climate atlas, a fledgling attempt to chart atmospheric trends to spur more environmentally friendly city planning.

The so-called environmental climate atlas, which makes a case study of Minato Ward, Tokyo, will be included in a heat island report to be released later this month, ministry sources said.

The atlas is designed to provide detailed climate data to help city planners encourage the development of cooler and cleaner cities, ministry officials said.

Temperature, wind direction and speed, land use, land cover, topographical features and heat energy release are among the factors calculated for Minato Ward.

Ministry officials said they hope to parlay this initial effort into a manual that individual municipalities can reference when drawing up climate atlases of their own.

Similar information has been used in Germany, where the concept has been put into practice, to ensure that buildings are not erected in a way that blocks "wind paths" that flush hot and stagnant polluted air from city centers.

Minato Ward was targeted for a number of reasons, officials said.

"The area is nationally famous and very highly developed, while at the same time undergoing rapid redevelopment. It is also along the bay and there was a wealth of data to work with," said Tetsuo Ishii of the Environment Ministry's Office of Odor, Noise and Vibration.

The northern part of the ward is prone to get warmer due to a higher amount of human activity and skyscrapers that could be obstructing bay breezes that might otherwise cool the city, said an expert who worked on the project.

In the case of Minato Ward, buildings could be erected to parallel known wind patterns and eke the most out of each gust, helping to cool central Tokyo.

Some experts predict that in the next decade, the city will regularly experience summer days with the mercury surging to 40 with potentially serious health ramifications for metropolitan denizens.

"The problem with city planning now is that developers do not look at the city as a whole, but just at the projects they are building on their land," said Takehiko Mikami, a climatologist and professor at Tokyo Metropolitan University.

For climate atlases to really make inroads and have a significant effect, policy promotion on the part of governments and a more holistic vision is needed, he said.

The ministry is considering drafting a similar climate atlas for Sendai, where the heat island urban warming effect has also been observed over the past two decades, later this year, officials said.