First Rainbows

First Rainbows 虹始見 (Niji hajimete arawaru) is the third and final micro season of the solar term "pure and clear" in Japan, as well as other Asian countries. It is a five-day micro season that in 2026 is from April 15th to April 19th. Overall, it is the 15th micro season of the year.

The micro season "First Rainbows" marks the period when the air has finally softened enough for rainbows to return to the sky. Through winter, the atmosphere is too dry and the sun too low for rainbows to form easily. But by mid-spring, the air grows moist, spring showers become frequent, and the sunlight breaks through in just the right way.

In Japanese poetry, the very first rainbow is called "hatsuniji", a late spring kigo. It is a signal that spring is nearing its end and Japan is quietly turning toward early summer. Spring rainbows tend to be pale, fleeting and delicate unlike the bold arcs of midsummer.