[Kochi Prefecture Shimanto City] Flowers That Color the Shimanto River Basin

1. Climate of Shimanto City
Shimanto City enjoys abundant forests, the clear Shimanto River, and the pacific ocean to its southeast, offering a rich natural environment. From 1991 through 2020, the average temperature was 16.5°C and the average annual precipitation was 2,877.9 mm, giving the area a warm, Pacific-type climate.

2. Flowers Nurtured by the Mild Climate
[Spring]
〇 Around late February, when the spring sun begins to warm the days, the Iruta Yanagi Grove in the Shimanto River lower basin turns a tender yellow-green as new buds swell, and some 10 million rapeseed flowers bloom across the willow groves like a yellow carpet. This is an iconic scene that announces spring in the Shimanto River watershed.

〇 By late March, the cherry trees at the hilltop viewing spot Tamesho Park come into full bloom. Lanterns are lit during the cherry blossom season, letting visitors enjoy the night blossoms as well. The Shimanto City Local Museum sits nearby, so while learning about local history you can also take in the views from its observation floor. (Shimanto City Local Museum opening hours/9:00–17:00, closed/Wednesdays)
At Shimanto River Sakura Zutsumi Park, neatly planted cherry trees and well-kept lawns invite visitors to sit and enjoy hanami while admiring the spring-bright Shimanto River. In the Shimanto River lower basin, plowing of rice fields begins around this time and the frogs start to call.

〇 When the cherry blossoms fall and the trees turn to leaf, look toward Kōzan-ji Temple to see the city flower, wisteria, paint the slopes purple. Kōzan-ji is also popular for hiking and birdwatching, and a park with play equipment makes it a favorite spot for families on holidays.

〇 In breezy May, roses and lilies cultivated by local residents brighten the pastoral inland landscapes in the Nishitosa area. Omiya Rose Garden welcomes visitors with about 500 rose bushes, while Nishitosa Yabukachi greets them with roughly 12,000 lilies.

〇 At this time of year, Shimanto Dragonfly Park shows dragonflies dancing above waters edged with water lilies and irises. Established in 1985 as the world’s first dragonfly reserve, the park has recorded 81 species of dragonfly. The Shimanto River Museum Akitsuio, attached to the park, exhibits insect specimens from around the world including dragonflies, alongside fish that inhabit the Shimanto River. (Shimanto River Museum Akitsuio opening hours/9:00–17:00, closed/Mondays)

[Early summer]
〇 Under rainy, cloudy skies in June, Yasunami Waterwheel Village delights visitors with the rhythmic clack of turning waterwheels while hydrangeas along the waterways blaze with color. Sheltered pavilions near the channels make it pleasant to sit and watch the hydrangeas and the rural scenery.
In the inland parts of Shimanto City, summer heat can be intense; when northwesterly winds blow, the foehn effect can raise temperatures and sea breezes from the pacific ocean have difficulty reaching inland, causing high heat. On August 12, 2013, Egawazaki recorded Japan’s highest temperature that year at 41.0°C.

[Autumn]
〇 In late September, when the sky seems a little higher, the Iruta Yanagi Grove is enlivened by clusters of red spider lilies (manjushage) that dye the area bright red, and autumn insects begin to call from the grasses. Around this time the severe summer heat gradually eases.

〇 In early November, when autumn deepens, beautiful fall colors appear along the ravines of the Kurozon River, a tributary of the Shimanto River.

[Winter]
Although Shimanto City benefits from a mild climate, snow does fall some winters in the mountain valleys and on plains opening toward the Bungo Channel, and mornings and evenings often dip below freezing. Daytime, however, tends to be mild with many pleasant, sunny winter days.

3. Events to Celebrate the Arrival of Spring
The Iruta Yanagi Grove, introduced above, hosts the Nanohana Festival. At the Nanohana Festival, the rapeseed flower groves spread like a yellow carpet and a variety of events are planned, including sales of local specialty products and wind band performances by junior and senior high school students. Please come and enjoy Shimanto River sightseeing when the rapeseed flowers are in bloom.