Name: Shimanto River Ultra Marathon Online Challenge [Year-end 1-Month 100km] (四万十川ウルトラマラソン オンラインチャレンジ【Year-end 1month 100km】)
Start: 2026-12-01
End: 2026-12-01

About the Event

Why not aim to finish alongside us, thinking of the Shimanto River, Japan's 'last clear stream'? Whether you've run the Shimanto River Ultra Marathon before, or have always dreamed of running it someday, we warmly welcome your participation. Entry fees vary by finisher gift tier. All tiers include a T-shirt. (T-shirt only ¥4,990; Shimanto udon noodles or long-sleeve T-shirt ¥6,990; pole-caught local bonito straw-seared tataki, or cap, or pants, or hoodie ¥8,990; Shimanto beef (sukiyaki-cut or yakiniku-cut) or Shimanto eel or original apparel set (cap, long-sleeve T-shirt, pants, hoodie) ¥12,990)

Races Offered

2month 100km Stage 1

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

2month 100km Stage 2

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

3month 100km

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

November Run 1month 100km

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

October Run 1month 100km

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

Training 1month 100km

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

Year-end 1month 100km

Dec 01, 2026

straighten

Distance — 100K

terrain

Type — Running

timer

110 days remaining

Weather History

These values represent the 3-year monthly averages for December in .

thermostat Temperature

-3.1° / 5.2°

wb_sunny Feels like

-7.6° / 1.1°

light_mode Avg sunshine hours

8h 1m

water_drop Avg rainfall

1.0 mm

ac_unit Avg snowfall

0.3 cm

air Avg wind speed

8.9 km/h (Light breeze)

opacity Sweat loss rate

Low

terrain Course conditions

Firm and slightly soft

sunny Max UV Index

Low (2.0)

humidity_mid Humidity

69.6%

wb_twilight Sunrise

06:46

nightlight Sunset

16:29

Hotels & Places to Stay

Runner Reviews

Read what other athletes have to say about their experience at the Shimanto River Ultra Marathon Online Challenge [Year-end 1-Month 100km] (四万十川ウルトラマラソンオンラインチャレンジ【Year-end 1month 100km】).

★ ★ ★ ★ ★