Microseason 23 of 72 · April 21–25
Lilacs perfume the evening
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
Lilacs perfume the evening
Common lilac fills parks with heavy fragrance after sunset.
- SESoutheast Subtropical
Reeds push through marsh water
Marsh grasses and river reeds surge skyward. Wetlands green over completely. The bottomland pulse accelerates.
- PNWPacific Northwest
Reeds Rise from the Wetlands
Emergent wetland plants shoot upward—sedges, rushes, and wetland violets. Skunk cabbage spathes fade as leaves expand. Common loon pairs now visible staging on Puget Sound.
- CACalifornia Mediterranean
Oak canopies full and green
Valley oak, live oak, and blue oak trees burst with full leaf. Interior Valley temperatures soar; photosynthesis peaks. Brown pelicans fish offshore.
- MWMountain West
New growth explodes across the montane
Aspen and cottonwood leaves unfurl in a brief green rush. Subalpine meadows green overnight as snowmelt saturates the soil.
- MPPlains Continental
Prairie Sedges Push Through Wet Soil
Standing water in prairie potholes triggers sedge and reed growth; cattails and bulrush emerge from muck.
- SWSouthwest Desert
Monsoon moisture approaches
Atmospheric pressure drops; clouds tower on southeast horizon; wind gusts.
- TRTropical / Sub-Tropical
Green shoots rise from the shore
Mangrove seedlings stretch upward; saltwort and glasswort greens show in marsh margins. Wet season peak arrives.
- AKAlaska Subarctic
Green spreads from the water up
Leaves emerge on willows and alders; sedges green the tundra. Birch and aspen still dormant, but buds are bright red with readiness.
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.