Rainbow Day (Niji no Hi)

What Is Rainbow Day?

July 16th is "Niji no Hi" (Rainbow Day) in Japan. The date was chosen through a wordplay (goroawase) on numbers: in Japanese, "7" can be read as "na" and "16" as "iro," combining to sound like "nanairo," meaning "seven colors" — the traditional Japanese description of a rainbow's colors.

The Origins of Rainbow Day

Mid-July also happens to fall around the time Japan's rainy season (tsuyu) typically comes to an end — a period when the combination of lingering moisture in the air and bright sunshine creates ideal conditions for rainbows to appear.

• Origin: A wordplay on "7" (na) and "16" (iro), together forming "nanairo" (seven colors)
• Seasonal significance: Falls around the end of the rainy season, a time when rainbows are especially likely to appear
• Theme: A day to hope that people — and people and nature — can be connected like the colors of a rainbow

Fun Facts About Rainbows

• How rainbows form: Rainbows appear when sunlight is refracted and reflected by water droplets in the air, splitting the light into a band of colors.
• The number of colors: In Japan, a rainbow is traditionally described as having "seven colors," but how many distinct colors people perceive in a rainbow varies across cultures and languages.
• Double rainbows: Under the right conditions, a fainter second rainbow — called a "fukuniji" (secondary rainbow) — can appear outside the main one, creating a double rainbow.

How to Spend This Day

July 16th is a good day to simply look up at the sky. After a rain shower, take a moment to scan the horizon for a rainbow — a small, simple pleasure that connects people everywhere.