Microseason · May 16–20
Roses open along the stoops
A five-day window of the year, read through nine North American climate regions.
Same week, nine climates
A microseason names a five-day window of the solar year. What that window 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 72-microseason calendar
A microseason is a five-day window of the solar year — long enough to notice something change, short enough that the change is specific. The year holds seventy-two of them, six per month, ordered by what the natural world is doing rather than what the clock says. Almanac calendars like this are an old American habit, kept by farmers, gardeners, and birders for centuries; Weather Story collects them into a single reference.
Each microseason is read through nine North American climate regions. The phenological events that mark a five-day window vary with ecology — the strawberries that open in the Northeast might coincide with the first magnolias dropping in the Southeast and the salmonberry blossoms unfurling in the Pacific Northwest. Same week, nine ecologies, nine readings.