Microseason 55 of 72 · October 1–5
Witch hazel blooms as others fade
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
Witch hazel blooms as others fade
Hamamelis virginiana — last bloom of the year, spidery yellow.
- SESoutheast Subtropical
Swamp waters recede
October opens dry; bald cypress swamps drain toward their seasonal minimum as the Piedmont's streams flow clear and cold.
- PNWPacific Northwest
Mushroom flush deepens
October rains unlock the duff. Matsutake, chanterelle, lobster, and hedgehog mushrooms fruit in abundance under Doug fir and hemlock.
- CACalifornia Mediterranean
Creeks begin to whisper
Dried creeks still dust-silent but atmospheric rivers visible on 10-day forecasts. Anticipation in the air.
- MWMountain West
October: the aspen stands reach their peak
Peak aspen color rolls across the ranges — San Juan Mountains, Sawtooth, Bitterroot — in a wave of gold and russet.
- MPPlains Continental
Prairie enters dormancy slowly
Wetlands and ponds dropping in water level. Tallgrass fading to bronze and russet. Sandhill cranes still moving through. Cool mornings frequent, but freezing nights rare.
- SWSouthwest Desert
Desert dries to deep gold
Wash flows cease; standing water vanishes as evaporation exceeds rare rainfall.
- TRTropical / Sub-Tropical
Easterly waves train across the basin
Tropical waves crossing the Atlantic from West Africa form named storms with reliable rhythm; these are the peak weeks of hurricane season.
- AKAlaska Subarctic
Deep cold settles across the land
October cold snap brings subzero nights; ice fog begins forming in valleys where water meets frigid air.
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.