Japanese 72-kō · May 16–20
竹笋生 takenoko shōzu
Bamboo shoots emerge
This microseason across nine climate regions
The Japanese kō names a single five-day window of the solar year. What it actually looks like on the ground depends on where you are. Below, the same calendar window read through each of nine North American climate regions.
- NENortheast Continental
Roses open along the stoops
Climbing roses begin flowering on brownstone trellises.
- SESoutheast Subtropical
Roses open on the Piedmont edge
Late spring blooms flood gardens and wild margins. Roses, azaleas, rhododendron peak. The overstory is emerald.
- PNWPacific Northwest
Shoots and Sprouts Rise in Ranks
Oxalis and other low herbs spread a carpet of clover-like leaves. Fern growth peaks—sword, bracken, lady ferns all at full stature. Cedar bark peels in long strips, scent rising on warm days.
- CACalifornia Mediterranean
Fog and sun in daily rhythm
Marine layer arrives at dawn, burns off by 10am. Afternoons brilliant and warm (70-75°F coast, 85-90°F interior). Fire danger begins to rise.
- MWMountain West
High country wildflowers peak
Peak bloom wave for lupine, paintbrush, and columbine across the montane and subalpine. Marmots whistle from talus slopes.
- MPPlains Continental
Roses Bloom Along the Shelter Rows
Rosa species (wild roses, introduced shrub roses) open across the region; honeysuckle perfumes the evening.
- SWSouthwest Desert
Saguaro crowns open white
Saguaro flowers open at the tips of the columnar arms — bats pollinate at night, white-winged doves and bees by day.
- TRTropical / Sub-Tropical
Flowers spill across the islands
Petals dominate—plumeria, royal poinciana, flamboyant tree, and bougainvillea in full bloom. Scent hangs in the humid air.
- AKAlaska Subarctic
The salmon run thickens
All five Pacific salmon species now active in major river systems. Commercial fisheries open. Grizzlies congregate at cascade-blocked passages.
About the Japanese 72-kō
The shichijūni kō (七十二候) divides the solar year into seventy-two five-day periods, each named after a small natural event: the first peach blossoms, the eastern winds melting the ice, the rotting grass becoming fireflies. The system was imported from China to Japan in the eighth century and refined by the Edo-period almanac Honchō Shichijūni-kō in 1685. Each kō is a tiny weather observation — a way of paying attention to the year five days at a time.
On Weather Story, every one of the seventy-two kō has been re-read for North American ecology. The Japanese poetic kernel stays the same; the regional content shifts with the climate. The earthworms that emerge in mimizu izuru show up in the Pacific Northwest as the cue for fern fiddleheads unfurling, in the Southeast as the season of crayfish chimneys, in the Plains as the trigger for first tornado watches.