Microseason 68 of 72 · December 6–10
Holly and winterberry persist
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
Holly and winterberry persist
Red berries are the last color standing in the bare landscape.
- SESoutheast Subtropical
Winter Locks the Land
Frost persists; ice forms on ponds and slow-moving waters throughout the coastal and piedmont zones. The air tastes metallic and sharp; true winter silence settles over the Southeast.
- PNWPacific Northwest
Winter cold locks the sky
Arctic outbreak possible. Temperatures plunge below 20°F in the lowlands. Columbia Gorge ice storms. Snowpack on Cascades grows thick.
- CACalifornia Mediterranean
Winter solstice season intensifies
Heaviest rains begin; sun reaches its lowest noon angle; winter formally dominates the California calendar.
- MWMountain West
Winter locks the high country
True winter arrives with sustained cold and snow coverage. The transformation is complete — the landscape is fully dormant, frozen, and silent beneath deep white.
- MPPlains Continental
Sky closes cold, winter reigns
True winter: overcast days, sub-zero wind-chill, frozen landscape. Snow geese and sandhill cranes complete their southbound passage.
- SWSouthwest Desert
True winter arrives
Freezing nights become standard. Palo verde bark tightens. Saguaro skins pucker as interior water conserves. The desert is locked.
- TRTropical / Sub-Tropical
Winter trades blow strong
Trade winds at peak intensity. Water temperature reaches annual low. Humpback whales arrive in Hawaii. Dry landscape fully revealed.
- AKAlaska Subarctic
Winter solstice approaches
The year's turning point nears. Interior sees <1 hour of pale daylight. Coastal areas slightly less dark. Aurora nearly constant.
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.