UPDATED June 2022.
Spending a day swimming at the beach is a wonderful way to escape the heat and humidity of Tokyo’s summer. Suprisingly, Tokyo does has two beaches of its own. Special events, like beach volleyball tournaments, are held at Odaiba Beach and children play at the water’s edge. However, water quality is poor, so swimming is not an option. Kasai Seaside Park contains Tokyo’s other beach. Families enjoy clam-digging there, but, again, the water is not clean enough for swimming.
Many Japanese swim and surf off the Miura Peninsula and the Shonan Coast – in Kamakura, Enoshima, Zushi, Hayama, Chigasaki, etc. In summer, many of these beaches are lined with temporary restaurant/bars staffed with friendly, young surfer-types. All serve tasty food and drinks, and some even offer live entertainment.
The Japanese government does water quality checks at these beaches, but I personally do not swim there. The amount of ocean-going traffic that passes close to the area, and the size of US & Japanese naval facilities nearby, makes me hesitant to go in past my knees.
Atami Sun Beach, in the Izu Peninsula, is my top choice for a day trip to the sea. By taking the shinkansen from Shinagawa (30-40 minutes), you can be floating in the ocean in just over an hour. It is also possible to travel there for around 2000 yen, one way, on the JR Tokaido Line (100 minutes by train) or an Express ‘Acty’ (86 minutes). Upon arrival, it is a 5 minute taxi ride, or 15 minute walk, downhill, from the station to the beach.
Resort hotels and palm trees sit beside Atami’s 400 meter long beach. The sand is darker and can get quite hot, so don’t forget some flip-flops or, even better, water shoes. Waves are minimal due to typhoon barriers – making this beach great for families. The water is very clear and there are a couple of platforms that visitors can swim out to. Restaurants, shops, and convenience stores are only minutes away.
One nice perk of swimming in Atami is that you can visit an onsen afterward and clean up before heading home.
There are many small beaches south of Atami, but it is better to stay overnight than to visit one in a day-trip. Shimoda, at the tip of the peninsula, is the most beautiful. Shirahama is a lovely white sand beach – the southern section is wide and lively; the northern section is narrow, rocky, and quiet. Overnight accommodations include a couple of larger resort hotels and many smaller inns and guesthouses.
Chiba Prefecture, on the other side of Tokyo Bay, also has many beaches to choose from – including popular Katakai, which lies in the middle of the Kujukurihama Coast, Japan’s second longest beach at 60 kilometers long. Unfortunately, most beaches in Chiba are not easy to reach by mass transportation. Onjuku is probably the easiest. It is possible to take a Limited Express Wakashio from Tokyo Station to Onjuku Station in 80 minutes, followed by a 10 minute walk. Beach huts and rental shops line the shore and there is a small waterpark for children. It’s also a popular surfing spot and Flying Sumo Surf Company provides lessons in English.
Be aware that attempting to drive to any of the destinations mentioned once Japanese kids are out of school (late July to the end of August) may result in hours stuck in a traffic jam.