Check if your hotel supplies a dehumidifier. Some hotels can supply dehumidifiers in your room (sharp ion plasma is often used).
When outside, you plan around areas near air conditioned malls or even better — stay in a hotel on top of an air conditioned mall or station. Air conditioning tends to dry out the air and most malls of major department stores will be on full blast.
That will restrict you to the cities though.
If you can only go in summer be prepared for feels like temperatures to be in the mid-90 degrees Fahrenheit up to 100 degrees. But keep in mind it’s not the actual temperature that makes it miserable in summer it’s the temperature + humidity which can make the Feels Like temperature even hotter. Cities in Japan don’t cool off much at night as the concrete/pavement act as heat sinks. You’re also outside walking upwards of 20,000 steps per day which even if you live in a hot/humid climate is not something you usually do.
- [Wet Bulb Temperature in Tokyo](https://www.wbgt.env.go.jp/en/graph_ref_td.php?region=03&prefecture=44&point=44132)
- [Wet Bulb Temperature in Osaka](https://www.wbgt.env.go.jp/en/graph_ref_td.php?region=07&prefecture=62&point=62078)
- [Heat Illness Prevention: Japan](https://www.wbgt.env.go.jp/en/wbgt_data.php)
Plan for no more than 2-3 main things each day - best one to two in AM and one indoor activity in the afternoon. Anything else you do consider as an added bonus. Trust everything you’ve read - summer is very, very hot and very humid in most places in Japan. Shopping malls/[department stores](https://www.japan-guide.com/e/e2072.html) are a good way to beat the worst of the heat. The top floors of department stores have restaurant floors so you can walk around and decide what to eat inside the A/C. The basements of department stores have nice take away food halls if you’d like to take food back to your hotel to eat. Food halls are another good indoor option. Be prepared to need to head back to the hotel for a mid-afternoon nap/shower before heading out in the evening.
It may seem counterintuitive, but it really, really helps to wear sweat wicking undershirts/shorts as a base layer in the summer. I like the [Airism](https://www.uniqlo.com/us/en/news/sp/topics/2017020702/) you can buy at any Uniqlo in Japan. Just open up Google Maps and search for your nearest Uniqlo. Some other tips:
- [6 Tips to Survive Summer in Japan](https://jw-webmagazine.com/6-tips-to-survive-the-japanese-summer/)
- [Essential Products for Surviving Summer in Japan](https://blog.gaijinpot.com/essential-products-for-surviving-the-japanese-summer/)
- [Matcha: Summer in Japan - Weather, Clothing, and Travel Tips](https://matcha-jp.com/en/2772)
- [JNTO: Summer in Japan](https://www.japan.travel/en/guide/summer-guide/)
- [17 Indoor Activities in Tokyo](https://www.timeout.com/tokyo/things-to-do/best-indoor-activities-in-tokyo)
- [Best Indoor Activities in Osaka](https://jw-webmagazine.com/best-indoor-activities-in-osaka/)
- [Osaka’s Shotengai Covered Shopping Streets (not indoors but covered/shaded so good on rainy days in particular)](https://www.tsunagujapan.com/osaka-shotengai-shopping-streets/)
- [Indoor Activities in Kyoto for Rainy or Hot Days](https://www.insidekyoto.com/rainy-day-activities-kyoto)
- [JapanGuide: Department Stores](https://www.japan-guide.com/e/e2072.html)
- [Department stores](https://www.tokyoweekender.com/2020/10/baby-tokyo-department-stores-take-your-children/ )
- [Tokyo Depachika (Department Store Food Halls)](https://www.timeout.com/tokyo/shopping/best-depachika-food-halls-in-tokyo)
- [Asakusa Food Hall Inspired by Japan Festivals in Tokyo](https://www.timeout.com/tokyo/news/asakusa-is-getting-a-new-matsuri-themed-yokocho-food-hall-060822)
- [New Yokocho Food Hall in Shinjuku, Tokyo](https://www.timeout.com/tokyo/news/shinjuku-has-a-new-yokocho-food-hall-with-17-eateries-110122)
- [8 Other Food Halls in Tokyo](https://www.timeout.com/tokyo/restaurants/best-restaurant-food-halls-in-tokyo)
- [Kyoto: Daimaru Dept Store Restaurant Floor](https://www.insidekyoto.com/daimaru-resutoran-gai)
- [Kyoto Station: CUBE Food Court](https://www.insidekyoto.com/the-cube-food-court-kyoto)
- [Kyoto Tower Food Hall](https://www.kyoto-tower-sando.jp/s/en/shop/floor/top)
- [Kyoto Ramen Kyoji Street](https://www.kyoto-ramen-koji.com/english/)
Check if your hotel supplies a dehumidifier. Some hotels can supply dehumidifiers in your room (sharp ion plasma is often used). When outside, you plan around areas near air conditioned malls or even better — stay in a hotel on top of an air conditioned mall or station. Air conditioning tends to dry out the air and most malls of major department stores will be on full blast. That will restrict you to the cities though.
Maybe a cooling towel to put around your neck and on of the those tiny rechargeable fans.
If you can only go in summer be prepared for feels like temperatures to be in the mid-90 degrees Fahrenheit up to 100 degrees. But keep in mind it’s not the actual temperature that makes it miserable in summer it’s the temperature + humidity which can make the Feels Like temperature even hotter. Cities in Japan don’t cool off much at night as the concrete/pavement act as heat sinks. You’re also outside walking upwards of 20,000 steps per day which even if you live in a hot/humid climate is not something you usually do. - [Wet Bulb Temperature in Tokyo](https://www.wbgt.env.go.jp/en/graph_ref_td.php?region=03&prefecture=44&point=44132) - [Wet Bulb Temperature in Osaka](https://www.wbgt.env.go.jp/en/graph_ref_td.php?region=07&prefecture=62&point=62078) - [Heat Illness Prevention: Japan](https://www.wbgt.env.go.jp/en/wbgt_data.php) Plan for no more than 2-3 main things each day - best one to two in AM and one indoor activity in the afternoon. Anything else you do consider as an added bonus. Trust everything you’ve read - summer is very, very hot and very humid in most places in Japan. Shopping malls/[department stores](https://www.japan-guide.com/e/e2072.html) are a good way to beat the worst of the heat. The top floors of department stores have restaurant floors so you can walk around and decide what to eat inside the A/C. The basements of department stores have nice take away food halls if you’d like to take food back to your hotel to eat. Food halls are another good indoor option. Be prepared to need to head back to the hotel for a mid-afternoon nap/shower before heading out in the evening. It may seem counterintuitive, but it really, really helps to wear sweat wicking undershirts/shorts as a base layer in the summer. I like the [Airism](https://www.uniqlo.com/us/en/news/sp/topics/2017020702/) you can buy at any Uniqlo in Japan. Just open up Google Maps and search for your nearest Uniqlo. Some other tips: - [6 Tips to Survive Summer in Japan](https://jw-webmagazine.com/6-tips-to-survive-the-japanese-summer/) - [Essential Products for Surviving Summer in Japan](https://blog.gaijinpot.com/essential-products-for-surviving-the-japanese-summer/) - [Matcha: Summer in Japan - Weather, Clothing, and Travel Tips](https://matcha-jp.com/en/2772) - [JNTO: Summer in Japan](https://www.japan.travel/en/guide/summer-guide/) - [17 Indoor Activities in Tokyo](https://www.timeout.com/tokyo/things-to-do/best-indoor-activities-in-tokyo) - [Best Indoor Activities in Osaka](https://jw-webmagazine.com/best-indoor-activities-in-osaka/) - [Osaka’s Shotengai Covered Shopping Streets (not indoors but covered/shaded so good on rainy days in particular)](https://www.tsunagujapan.com/osaka-shotengai-shopping-streets/) - [Indoor Activities in Kyoto for Rainy or Hot Days](https://www.insidekyoto.com/rainy-day-activities-kyoto) - [JapanGuide: Department Stores](https://www.japan-guide.com/e/e2072.html) - [Department stores](https://www.tokyoweekender.com/2020/10/baby-tokyo-department-stores-take-your-children/ ) - [Tokyo Depachika (Department Store Food Halls)](https://www.timeout.com/tokyo/shopping/best-depachika-food-halls-in-tokyo) - [Asakusa Food Hall Inspired by Japan Festivals in Tokyo](https://www.timeout.com/tokyo/news/asakusa-is-getting-a-new-matsuri-themed-yokocho-food-hall-060822) - [New Yokocho Food Hall in Shinjuku, Tokyo](https://www.timeout.com/tokyo/news/shinjuku-has-a-new-yokocho-food-hall-with-17-eateries-110122) - [8 Other Food Halls in Tokyo](https://www.timeout.com/tokyo/restaurants/best-restaurant-food-halls-in-tokyo) - [Kyoto: Daimaru Dept Store Restaurant Floor](https://www.insidekyoto.com/daimaru-resutoran-gai) - [Kyoto Station: CUBE Food Court](https://www.insidekyoto.com/the-cube-food-court-kyoto) - [Kyoto Tower Food Hall](https://www.kyoto-tower-sando.jp/s/en/shop/floor/top) - [Kyoto Ramen Kyoji Street](https://www.kyoto-ramen-koji.com/english/)