Microseason 65 of 72 · November 21–25
First flurries dust the rooftops
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
First flurries dust the rooftops
Trace snow possible — the city holds its breath.
- SESoutheast Subtropical
First Frost Grips the High Ground
Killing frosts arrive throughout the Appalachian regions and Piedmont. Tender evergreens wilt; frost flowers crystallize on plant stems and the last of the insects disappear.
- PNWPacific Northwest
Heavy rains mask the stars
Pineapple Express atmospheric rivers surge in. Rainfall rates exceed 1 inch per 6 hours. Clouds solid to 2,000 feet. Streams rise hard.
- CACalifornia Mediterranean
Thanksgiving rains swell the valleys
Heavy atmospheric rivers drench the coast; creeks swell; landscape emerges from brown to green in days.
- MWMountain West
Snow returns to the peaks
Early winter snowfall blankets the high passes and upper summits. Valleys still bare, but the mountains turn white again as moisture returns.
- MPPlains Continental
First snow falls soft
Light snow dusts the prairie and corn stubble. Snow geese and Canada geese stream south through the Central Flyway in massive flocks.
- SWSouthwest Desert
Pacific storms break the drought
First significant rains arrive from ocean systems. Creeks flow briefly. Dust—held a moment by moisture—settles. The smell of wet earth rises.
- TRTropical / Sub-Tropical
Dust veil settles
Saharan dust intensifies; visibility thins. Dry continental air dominates the region. Reefs experience reduced light penetration.
- AKAlaska Subarctic
Deep cold grip solidifies
Temperatures plummet to -20°F and lower. The year's coldest period approaches. Aurora burns brightly in constant darkness.
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.