Nihyakutōka — Japan's 210th-Day Typhoon Watch

What Is Nihyakutōka (the 210th Day)?

Around September 1st falls "Nihyakutōka" (二百十日), literally "the 210th day" — one of the traditional Japanese zassetsu, seasonal markers that supplement the 24 solar terms. It marks the 210th day counted from Risshun (the first day of spring, around February 4th). Depending on the year it can fall on August 31st; from 2021 to 2056, it falls on September 1st in years whose number leaves a remainder of 2 or 3 when divided by 4. This period coincides with both the rice plants' flowering stage and the height of typhoon season approaching mainland Japan, so farmers have long treated it as one of the most dangerous "unlucky days" of the year.

The "Three Great Unlucky Days" for Farmers

• Hassaku: the 1st day of the 8th lunar month — a day to celebrate the rice harvest while watching for typhoons
• Nihyakutōka: 210 days after Risshun, around September 1st
• Nihyakuhatsuka: 220 days after Risshun, around September 11th

For centuries, farmers used these three days to walk their fields and pray to the gods for protection against storm damage just before harvest.

Why Is "Disaster Prevention Day" on September 1st?

Japan's Disaster Prevention Day (Bōsai no Hi, established 1960) falls on September 1st because the devastating Great Kanto Earthquake struck on that day in 1923. Since the date also coincides with Nihyakutōka, traditionally associated with typhoons, the day is said to carry an added reminder to stay prepared.

Nihyakutōka in Literature

In 1906, novelist Natsume Sōseki published a short novel titled "Nihyakutōka," a dialogue-driven story set against the backdrop of Mount Aso. The story centers on the conversations of two young men attempting to climb Mount Aso amid the stormy weather of Nihyakutōka.

Tips for Marking This Day

• Use Nihyakutōka as a prompt to check typhoon forecasts and restock your emergency disaster kit
• Take a walk to see the golden ears of rice ripening in the fields
• Read Natsume Sōseki's novel "Nihyakutōka"
• Talk with family about what "unlucky days" meant to people in the past and how they respected nature

A Day of Wisdom — "Prepare Before Disaster Strikes"

Statistically, typhoons don't always arrive exactly on Nihyakutōka. But the fact that people prepared anyway — embodying the spirit of "there's no regret if you're ready" — is precisely why this oddly specific 210th day has survived in the calendar for centuries. On September 1st, look up at the sky and reconnect with the deeply attuned relationship the Japanese have long held with nature.