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Cooling Off With Water On Japan’s Hot Summer Days

Cooling Off With Water On Japan’s Hot Summer Days

Translated by Briony Dunbar

Written by MATCHA-PR

2015.05.30 Bookmark

Japanese summers are intensely hot, so let's go over some of the ways to cool off - using water!


In Japanese summers both the temperature and humidity get quite high and, particularly in July and August, you might start to feel like you're being boiled alive when outside. To relieve the heat, many tricks have been practiced in Japan since the olden days.

Japan is especially rich with water, so much so that it is called a major power when it comes to water resources. As a result, there are many water-based counter-measures for heat to be found throughout Japan.

Dry Mist: Lower the City's Central Temperatures


Pictured above is the latest device that produces an artificial mist, called “Dry Mist”. You can find them in large cities such as Tokyo, where the heat rises easily due to a lack of urban open spaces.

This device cools you by creating a latent heat of vaporization when the mist evaporates, which contributes to lowering the atmospheric temperature. Although it is called mist, it immediately evaporates, so it doesn’t get people wet.

The pioneer of this technology is Japanese, and "Dry Mist" is a counter-measure technology for Japan’s characteristic heat.

Uchimizu: An Ancient Trick

Uchimizu is a method of cooling the temperature around you by sprinkling water in places such as at the entrance of your house or business. It is a Japanese custom that has been practiced since the olden days as a means of cooling down the hot days of summer. When the sprinkled water evaporates, it takes away the surrounding heat and lowers the temperature. In other words, uchimizu uses the same principle as the modern “Dry Mist” technology.

Photo by Nemo's great uncle

Photo by Danny Choo

The important thing here is that the water that is used is not tap water, but so called "Secondary Usage Water" - water that has already been used once, such as the left over water from baths or laundry, collected rainwater and the like. From an environmental and economical perspective, reusing the water in this way is both cost effect and eco-friendly.

The number of municipalities that are paved with roads suitable for Uchimizu is rising.

The number of municipalities that are paved with roads suitable for uchimizu is rising.

Uchimizu Events are held all over Japan!

Uchimizu was originally an individual activity, but now Uchimizu Events are being held in communities all around Japan. Here we will focus on introducing events in Tokyo.

Daimaruyu Uchimizu Project: around Tokyo Station


The area full of office buildings surrounding Tokyo Station is generally called Daimaruyu (大丸有), using the reading of the first kanji of the Otemachi (dai, 大手町), Marunouchi (maru, 丸の内) and Yurakucho (yu, 有楽町) areas.


Tokyo is a concrete jungle and as a result of the thermal energy that accumulates during the day, the nightly temperature in Tokyo is almost the same as day. Because of this, the organisation that manages the area holds an Uchimizu event every week in the summer season with this as its core.


Depending on the event, yukatas are available to rent, so we really recommend that travelers with an interest in Japanese traditional clothing participate.

Kasumi Terrace’s Uchimizu Club Kasumigaseki


Kasumi Terrace’s Uchimizu Club is an Uchimizu initiative that is being implemented in Kasumigaseki Sanchome South District (an area full of office buildings) with the cooperation of central government agencies and civilian enterprises, as an occasion in which you can contribute to your area.


The Children’s Kasumigaseki Field Trip Day is held as an open participation event on an appointed day by a government office, in which people neighborhood kindergarten age children visit the local government office to see what government workers do there. The parents/guardians that attend may also participate in this event. As the sprinkling of water is carried out by both adults who work during the day and children, it seems it has also become an occasion in which both parties can intermingle.

Uchimizukko Gathering Akihabara


As the act of uchimizu is a tradition from the olden days, many practice it at events whilst wearing a yukata, but at the Uchimizu event held in the Akihabara area, the atmosphere is a little different.


Why, you ask? It is because this Uchimizukko Gathering is held by cute maids and cosplayers who work in Akihabara. It functions not only for lowering the area’s temperature, but also as an event that connects all the streets in Akihabara.

This time round, we introduced the latest Japanese technology “Dry Mist”, and the traditional Japanese culture of uchimizu at different events in Tokyo, though these events are held all across Japan. When in Tokyo, why not beat the heat by experiencing some of these cool water-based activities?


Dry Mist Map

Shin-Marunouchi Building(Marunouchi area)
Address: 100-0005 Tokyo, Chiyoda-ku, Marunouchi 1-5-1
Website: Marunouchi Dry Mist

Mitsubishi Ichigokan Museum(Marunouchi area)
Address: 100-0005 Tokyo, Chiyoda-ku, Marunouchi 2-6-1
Website:Mitsubishi Ichigokan Museum

Roppongi Hills 66 Plaza(Marunouchi area)
Address: 106-0032 Tokyo, Minato-ku, Roppongi 6 chome, Roppongi Hills
Website: Roppongi Hills

Akihabara Crossfield
Address: 101-0021 Tokyo, Chiyoda-ku, Sotokanda 4-14-1
Website:Akihabara Crossfield

Uchimizu Events
Daimaruyu Uchimizu Project
Open period: last third of July to mid-August
Location: Otemachi・Marunouchi・Yurakucho Area
Website: Daimaruyu Uchimizu

Kasumi's Uchimizu
Open period: the first third of August
Location: Kasumigaseki Common Gate Central Plaza

Uchimizukko Festival
Open period: the first third of August
Website: Uchimizukko Festival (Japanese only)

The information presented in this article is based on the time it was written. Note that there may be changes in the merchandise, services, and prices that have occurred after this article was published. Please contact the facility or facilities in this article directly before visiting.

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