[For Seniors] Trivia Quiz & Fun Facts About the Rainy Season (Tsuyu)

Frog

Because frogs often croak before it rains and during the rainy season, it’s said that their calls signal changes in the weather. Resistant to humidity and becoming more active when it rains, frogs have long served as a kind of weather forecaster.

65％

Mold tends to develop when humidity exceeds 65%. It does not grow below 55% humidity, but it doesn’t die either, so during the rainy season when humidity is high, frequent ventilation and dehumidification are important.

pickled plum

During the rainy season, humidity rises and food spoils more easily. For this reason, pickled plums (umeboshi) have long been valued. Thanks to their acidity and salt content, umeboshi have preservative effects and are suitable for long-term storage.

A wish for it to rain

Teru teru bozu are usually hung with the wish for clear weather, but hanging them upside down carries the opposite wish—for rain. In some cases, such as among farmers, it can serve as a form of rainmaking.

Mid-Showa period (1950s)

Observations and announcements of the start and end of the rainy season have been officially conducted by the Japan Meteorological Agency since 1951. You can check them on the agency’s website. Before that, there were no official announcements.

Edo period

The word baiu, which refers to the rainy season, is of Chinese origin. It was introduced to Japan during the Nara period, but by the Edo period it had already come to be called tsuyu as well, and that became the common name.