Snow circle
雪輪 yukiwa

Rounded snowflake rings stand for purity and the promise of a good harvest after heavy snow; used in winter, and in summer for a cool feeling.
Heian period (snow imagery); popular in the Edo period
Snow was welcomed in court culture as a sign of a good harvest. The rounded snow-ring outline, often said to reflect the six-fold snow crystal, was used from at least the Momoyama period and spread widely among Edo townswomen. Interest grew after the daimyō Doi Toshitsura published microscope drawings of snow crystals, Sekka zusetsu, in 1832, which also launched the more literal sekka (snow-flower) pattern.
Used on kimono and yukata regardless of season; in summer it gives a cool feeling.