If the city feels hotter to you in the summer, you're right. The
Japan Meteorological Agency has proved that all the asphalt and
tall buildings and exhaust heat are indeed to blame. "Urban heat
islands" raised the daily August temperatures by 1 to 2 degrees
in Japan's three biggest megalopolises of Tokyo, Osaka and
Nagoya, the JMA said July 9. This is the first time the JMA has
analyzed the effects of urban heat islands, where asphalt,
buildings and heat from the exhaust of automobiles and air
conditioners and other factors contribute to a rise in
temperatures. The JMA used data from last August to simulate air
temperatures on the assumption that all ground surface was
covered by grassland and that there was no exhaust heat from
human activities in the three megalopolises, and compared the
numerical outcomes with what was actually recorded. The urban
heat islands accounted for rises of about 2 degrees in the
cities' central areas and about 1 degree on their outskirts, JMA
officials said. It is believed that a