Summer is a great season to see “sea of clouds” in Kussharo Caldera and Mashu Caldera. Clouds are fog that forms off the coast of Kushiro. When the southerly winds (generated by the Pacific High-Pressure System) pass over the warm Kuroshio Current (flowing from the Honshu – Japan’s main island), the air becomes warm and moist, and when this air passes over the cold Oyashio Current (flowing from the Kuril Islands), it cools and becomes fog. This fog arrives in Kushiro City on the southerly winds and it is known as “sea fog”. The sea fog moves on to Kushiro wetland and then to two calderas – Kussharo and Mashu. If you drive up to one of the outer rim of Kussharo Caldera – Bihoro Pass, Tsubetsu Pass or Mt. Mokoto, or the outer rim of Mashu Caldera – Lake Mashu Observation Deck, you will be amazed by the spectacular views!!
