Clouds of yellow sand carried by strong winds from China were observed across the nation from late Monday night to Tuesday morning, the first time the phenomenon has been observed nationwide in the autumn in six years, the Meteorological Agency said.
Clouds of yellow sand were seen in more than 40 sites, mainly in western Japan and the Hokuriku region on the Sea of Japan coast, the agency said.
The phenomenon is usually observed in March and April and primarily in western Japan.
The agency said the clouds of sand, originating in northwestern Chinese and Mongolian deserts, were carried to the Japanese archipelago by winds caused by a cold front around Hokkaido.
Some locations, including Esashi, Hokkaido, and Kanazawa, Ishikawa Prefecture, observed clouds of yellow sand for the first time ever in the fall.
Because of the clouds, the visibility dropped to 3 km in Nagasaki, the agency said.
Yellow sand clouds also affect the Korean Peninsula. This year, in South Korea, they caused sore eyes and throats and cancellation of some flights.