Microseason 69 of 72 · December 11–15
Shortest day approaches
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
Shortest day approaches
The solstice is days away — darkness is almost at its peak.
- SESoutheast Subtropical
Wildlife Retreats to Shelter
Black bears, raccoons, and other mammals enter deep hibernation or torpor in dens, hollow trees, and burrows. The forest floors are silent except for wind and rare animal movement.
- PNWPacific Northwest
The days reach their minimum
Winter solstice window. Sunrise after 7:50 AM, sunset before 4:20 PM. 8.5 hours of daylight. Marine layer deepens daily.
- CACalifornia Mediterranean
Deep winter: rivers at flood stage
Rivers crest with runoff; coastal cliffs take pounding swells; monarch overwintering colonies cluster tight on eucalyptus groves.
- MWMountain West
Elk withdraw to winter range
Bull elk, exhausted from the rut, move to lower elevations with softer snow. High meadows stand silent, abandoned until spring thaw.
- MPPlains Continental
Darkness deepens, life retreats
Ground frozen deep. Bears, badgers, and ground squirrels sealed in winter burrows. Only wind and silence move across the white plain.
- SWSouthwest Desert
The shortest day looms
Winter solstice approaches. Days shrink to 9.5 hours of sunlight. Shadows grow long and horizontal. Desert light turns amber at noon.
- TRTropical / Sub-Tropical
Solstice approaches in green silence
Water stress at seasonal peak. Vegetation enters maximum dormancy. Days shortest. Solar angle lowest. Tropical nights cool noticeably.
- AKAlaska Subarctic
Bears deep in winter sleep
Hibernating bears have entered torpor weeks ago. Denning across tundra and taiga. Interior temperature approaches -40°F.
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.