Koiji Beach offers swimming opportunities during the summer season, and as one of Noto's more famous beaches, it typically has better facilities than completely hidden spots. However, always verify current conditions, as water safety depends on weather, tides, and season. Check whether lifeguards are on duty during your visit, as services may be seasonal. The beach's popularity means more people are usually around, which can be reassuring. Pay attention to any posted warning flags or signs, and avoid swimming during rough weather or strong currents common along the Noto coast.

The best weather for visiting Koiji Beach typically occurs from late spring through early autumn (May to October), with July and August offering the warmest conditions for swimming. However, the beach is renowned for its sunset views, which can be spectacular year-round on clear days. Late spring and early autumn often provide comfortable temperatures with fewer crowds than peak summer. For the most dramatic sunsets, visit during clear weather and check sunset times to arrive with ample time to enjoy the changing colors. Golden hour photography is particularly stunning here.