The old custom of sprinkling water with a ladle or by hand on the ground, called “uchimizu”, is a well-known example of the use of water in Japan’s daily living. People used to sprinkle water in their house entrances and gardens or in front of their shops to lay the dust and ease the heat, which sometimes implies welcoming of guests.

Water has a high heat of vaporization. As sprinkled water evaporates, it takes heat away from the ground.

Mission Uchimizu was launched as a great social experiment in 2003 in order to prove the hypothesis that we can lower the summer temperature by two degrees Celsius if one million people simultaneously do uchimizu (sprinkle water) on streets and gardens.

Following the fruitful outcomes of the experiment in 2003, Mission Uchimizu has become a social action that millions of people in Japan take part in and doing uchimizu through the summer every year.

Climate-adaptive Mission Uchimizu

In recent years, we have experienced many hot days like summer during the season called Spring. It is observed that the global average temperature has been increasing. Extreme weather events and climate disasters take place across the planet.

To adapt to these changes as our climate action, Mission Uchimizu has been evolved.

A renewal version of Mission Uchimizu calls for practicing uchimizu every hot sunny day in any seasons.
It is hard to resolve climate impacts immediately. However, we believe that climate-adaptive Mission Uchimizu can make a difference to people’s climate awareness.
We have embarked on our new journey towards a sustainable future.