The Jomon Sugi (縄文杉) is the largest and best known of the ancient Yakusugi cedars on the UNESCO World Heritage island of Yakushima (屋久島) off the southern coast of Kagoshima Prefecture, 22.2 metres tall with a girth of 16.1 metres, standing at 1,328 metres in the mountain interior in a primeval rainforest where the saying goes that "it rains 35 days a month". Its age depends on the method used, and Yakushima Town gives a range of 2,170 to 7,200 years while the Kyushu Regional Forest Office of the Forestry Agency puts it at 1,300 to 3,600 with a central figure of 2,400. The trail from the Arakawa Trailhead is 22 kilometres round trip with around 700 metres of ascent and takes 8 to 10 hours, the first 8 kilometres running along the Anbo forest railway, the only forest railway still working in Japan's national forests, and the upper section climbing a steeper path of ladders and roots. It passes the Wilson's Stump, the hollow remains of a giant cedar that Yakushima Town records as felled about 300 years ago and named after the American botanist who surveyed the yakusugi in the Taisho era, the Daio Sugi Great King Cedar radiocarbon dated in 1983 to 3,030 years give or take 160, and the Meoto Sugi Husband and Wife Cedars, two trunks joined by a shared branch, before reaching a wooden observation deck set back from the base of the Jomon Sugi to keep feet and hands off its roots. The wider island was registered in 1993 as Japan's first UNESCO World Natural Heritage Site and has mountain peaks rising close to 2,000 metres above the Pacific. Summer brings the heaviest rain, the highest humidity and the most heat of the year to this walk, so it is started before dawn to be off the mountain before the afternoon thunderstorms build. The first Arakawa shuttle buses leave the Yakusugi Museum at 5:35, which means a hotel departure around 5:00 and a night in Anbo beforehand if you want the earliest one. Private vehicles are barred from the trailhead road every year from 1 March to 30 November, so the shuttle is the only way in, at ¥2,000 one way or ¥3,000 return, each of which includes the ¥1,000 mountain conservation fee. Tickets are sold in advance rather than on the bus, at the Anbo, Miyanoura and airport information offices, the Yakushima Environmental Culture Village Centre and the Yakusugi Museum bus stop. Most walkers go with a licensed local guide, and day trip prices are set per group so the cost per person falls sharply as the party grows, with bus fares, the conservation fee and lunch normally charged on top. Trekking shoes, full rain gear and a covered daypack are the minimum, and rental shops in Miyanoura and Anbo carry them. From Kagoshima the flight to Yakushima Airport takes around 40 minutes, with the Toppy and Rocket jetfoils to Miyanoura Port taking 1 hour 50 minutes direct and up to 2 hours 45 minutes on sailings that call at Tanegashima.

Takachiho Gorge (高千穂峡) runs for around 7 kilometres through the town of Takachiho in Nishiusuki District in the north of Miyazaki Prefecture, where the Gokase River has cut down through pyroclastic flow deposits thrown out by eruptions of Mount Aso and left walls of columnar jointing standing on both banks. Takachiho Town gives the average cliff height as around 80 metres, rising to about 100 metres at the tallest points, and the gorge was designated a national place of scenic beauty and natural monument in 1934 under the name Gokasegawa Kyokoku, becoming part of the Sobo-Katamuki Quasi-National Park in 1965. The Manai Falls (真名井の滝) drop about 17 metres straight into the river at the narrowest point and are on the list of Japan's 100 selected waterfalls. Rowing boats are what most people come for in summer, taken out from the boat house in the gorge to sit under the falls with the rock closing overhead. The town charges ¥4,100 to ¥5,100 per boat for 30 minutes, with a maximum of three people or four where preschool children are included, and ¥1,000 for every additional 10 minutes. Boats are booked in advance through the tourism association's online reservation system rather than bought at the water's edge, and they are suspended whenever the river runs high, which in a Kyushu summer means the tail of the rainy season in July and the days around any typhoon, so keep a fallback in the plan. A walking path of about 1 kilometre runs the length of the gorge for anyone who does not get on the water, and the shade and the river make it noticeably cooler down there than in the open country above. Note that the outdoor lighting along the gorge is switched off for several weeks in late spring so the fireflies can breed, a suspension that ran from 26 May to mid June in 2025. All four car parks now charge, the first at Oshioi and the second at Ararugi at ¥1,000, and the third at Ohashi at ¥800 and the fourth at Oshikata at ¥500 since 1 April 2026, the last two with the first 60 minutes free.

Yufuin (由布院) is a highland hot spring resort town in Yufu, Oita, at the foot of the twin peaked Mount Yufu, with around 850 hot springs feeding the town's many ryokan that rank Yufuin among Japan's top three onsen destinations in both volume of water and number of sources. The Kinrinko Lake (金鱗湖) at the edge of the town is the most photographed spot in Yufuin, a small lake fed by fresh water springing from the lake floor and a hot spring streaming in that keeps the water temperature high through the year, with a small torii gate on the lakeshore and the twin peaks of Mount Yufu rising behind. The famous mist that rises from the lake in the early morning is an autumn and winter phenomenon when the cold outside air meets the warm lake water, with summer visits offering a different character of green pastoral scenery around the lake and the wider basin instead. The Yunotsubo Kaido (湯の坪街道) main street between the train station and the lake is lined with souvenir shops, galleries, restaurants and the Yufuin Floral Village shopping area, with the alkaline simple hot springs at most ryokan offering open air baths looking out to Mount Yufu. From Hakata Station the Yufuin no Mori Limited Express runs directly to Yufuin Station in around 2 hours 16 minutes for ¥5,690.

The Kerama Islands are a group of small islands approximately 30 kilometres west of Naha and the coral reefs that surround them are designated a national park and widely considered the finest accessible diving and snorkelling destination in Okinawa. Summer is the primary reason to visit specifically because the warm water temperatures through July and August bring the coral reef ecosystem to its most active and most biodiverse seasonal condition, the coral spawning events that occur through the summer months, the visibility that reaches 30 metres or more in the clear Kerama waters, and the density of marine life including sea turtles, manta rays, and the full range of tropical reef fish makes summer diving and snorkelling here a world class experience. The 座間味島 (Zamami Island) and 渡嘉敷島 (Tokashiki Island), the two most accessible of the main Kerama islands, have small beaches of extraordinary quality that are swimmable directly from shore without a boat, and the combination of the beach swimming and the guided snorkelling tours that operate from both islands through summer gives the Kerama visit a range of water engagement that suits different levels of experience and commitment.

Miyako Island sits approximately 300 kilometres southwest of the Okinawa main island and is home to some of the finest beaches and clearest water in Japan, a combination that summer makes most specifically appropriate and most fully accessible. The 与那覇前浜ビーチ (Yonaha Maehama Beach) on the southwestern coast of the island, consistently rated among the finest beaches in Japan for the quality of the white sand and the clarity of the shallow turquoise water, is at its most swimmable and most alive through July and August when the water temperature and the summer conditions make extended time in and around the water pleasurable rather than simply scenic. The 伊良部大橋 (Irabu Bridge), the longest toll free bridge in Japan at 3.5 kilometres, connecting Miyako Island to the adjacent Irabu Island, gives views across the summer sea from both sides of the bridge that in the right light conditions produce one of the most vivid turquoise water panoramas available from a road surface anywhere in Japan. The coral reefs surrounding Miyako Island support summer diving conditions of exceptional quality and the combination of the beach, the bridge, and the reef gives the island a summer range that rewards at least two to three days of exploration.

Kouri Island in summer is most specifically worth visiting for the beaches on the northern and eastern coasts of the small island that are swimmable and snorkelable directly from shore, the 古宇利ビーチ (Kouri Beach) on the northern tip of the island has sand and water of exceptional quality and in summer the water temperature and clarity make it one of the most accessible and most rewarding swim and snorkel beaches reachable by car from the northern Okinawa main island without a ferry crossing. The view from the 古宇利大橋 (Kouri Bridge) crossing in summer, looking down into the turquoise shallow water on both sides of the causeway with the island visible ahead, is most dramatically coloured through July and August when the sun angle and the summer light intensity give the water its most vivid and most saturated blue green colour. The 古宇利オーシャンタワー (Kouri Ocean Tower) on the island hilltop gives the most elevated view across the summer sea and the surrounding island coastline that the ground level beach experience cannot provide, and the combination of the tower view, the bridge crossing, and the beach swimming gives summer on Kouri Island a range that rewards spending a full day on the island rather than simply crossing the bridge.

冷や汁 (Hiyajiru) is Miyazaki's answer to working through a subtropical summer. Grilled fish, usually sea bream or horse mackerel, is flaked and pounded into miso with toasted sesame, sometimes peanuts, then let down with cold dashi and poured over 麦飯 (mugimeshi), barley rice, with cucumber, shiso and myoga through it. It came from farm labour. The origin is field workers putting raw miso on barley rice and adding water, because there was no time and no appetite for anything hot, and rice was scarce enough in rural Miyazaki that barley was the staple. Grilling the miso first is what lifts it from expedient to good. It is still served at family gatherings at Obon, and it is now on menus across the prefecture through the summer. Cold, salty and savoury rather than refreshing in a sweet way, which is why it works when nothing else appeals.

城下かれい (Shiroshita Karei) is マコガレイ (makogarei) caught in one specific patch of 別府湾 (Beppu Bay), off 日出町 (Hiji Town) in Oita, and the name means below the castle. Fresh water wells up through the seabed there from springs beneath 日出城 (Hiji Castle), and the mix of fresh and salt water is the local explanation for the fish, which is white, firm fleshed and without the muddy note flounder can carry. The season runs April to September and the best of it is May into early July. It has a documented history as a tribute fish, with dried specimens sent to the shogun's household in the Edo period and live fish carried up to Edo for the Boys' Festival in leap years. It is eaten as 洗い (arai), sliced thin and shocked in cold water so the flesh tightens, or simply grilled, and the restaurants and ryokan along the Hiji seafront run a set menu around it through the season.

岩牡蠣 (Iwagaki) is the oyster that runs on the opposite calendar to the one most people know. The season is May to mid August, when the farmed winter oyster of Hiroshima is out of condition, and almost all of it is wild rather than cultivated, which means divers go down and lever it off the rock by hand. It takes two to three years to reach size against roughly one for the farmed kind, and it grows much larger and thicker shelled, with a deeper, creamier and more mineral flavour than a winter oyster. In Kyushu the names to look for are the 五島列島 (Goto Islands) off Nagasaki, the Ariake Sea side of Saga, and the 雲仙 (Unzen) coast, where they are sold as summer oysters. Eaten raw off the shell with citrus, or grilled in the shell over coals at the roadside 牡蠣小屋 huts along the coast.

Mango is Okinawa's summer gift fruit. The main variety is アップルマンゴー (apple mango), the Irwin, grown under greenhouse cover across the islands, and the method is what puts the price on it. The fruit is left on the tree until it separates on its own, caught in a small net tied beneath it, so it is never picked early. That gives a fruit with no fibrous edge, heavily perfumed, and soft enough to eat with a spoon. The season runs June to August with the peak in July. Most of the crop is graded and boxed as 贈答用 (gift fruit) and sold at prices that reflect that, but the 訳あり (blemished) grade sold at roadside stands and farmers' markets on the islands is the same fruit at a fraction of the price. It is eaten fresh, and turned into shaved ice, parfaits and juice across the islands through the summer.

呼子 (Yobuko) is a small port on the Genkai Sea coast of Saga that has built itself around one dish. The squid is ケンサキイカ (kensaki ika), swordtip squid, in season from May to July, and it is served as イカの活き造り (ika no ikizukuri). The squid is taken live from a tank, sliced, and put on the plate still moving, the flesh so fresh it is transparent rather than white and the texture closer to crunchy than soft. The service started at a Yobuko restaurant in the 1960s and the town now runs on it. The order comes in two parts, because the body goes out raw and the legs and wings go back to the kitchen to return as tempura or salt grilled, so one squid is eaten twice. Yobuko also runs a long established morning market along its main street, and the squid is dried on frames in the sea wind above the harbour.

Pineapple is grown commercially in Japan essentially only in Okinawa, which needs acidic soil and a subtropical climate, and the season runs May to August. The harvest moves geographically as it goes. It opens in the 八重山 (Yaeyama) islands in the far south and then works north to 東村 (Higashi Village), 国頭村 (Kunigami) and Nago on the main island, where the red clay soil of the Yanbaru suits it. Higashi Village is the centre of it, with around 180 growers and a pineapple festival in the summer. Varieties differ more than people expect. ボゴール, the snack pineapple, pulls apart in the fingers without a knife, and ピーチパイン is pale and smells of peach. Unlike the mango it is a field crop rather than a greenhouse gift fruit, sold cut at roadside stands and juiced everywhere, and the fruit is picked ripe because it does not sweeten after cutting.