Microseason 49 of 72 · September 1–5
School buses reappear
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
School buses reappear
The city's rhythms shift — earlier mornings, quieter parks.
- SESoutheast Subtropical
Harvests begin in earnest
September opens with pecan hulls splitting on Coastal Plain orchards; cicadas fall silent as the season pivots.
- PNWPacific Northwest
Rivers quicken with silver
Chinook salmon begin their upstream run, their muscular forms flashing in clear rivers. The first schools arrive with purpose, sensing spawning grounds.
- CACalifornia Mediterranean
Fire season intensity
Chaparral browns completely; fire potential highest. Santa Ana winds still absent but coming.
- MWMountain West
Elk descend from summer high meadows
Cooling alpine drives elk herds downslope toward pine-aspen transition; their movement signals autumn's true start.
- MPPlains Continental
Corn tassels and heavy skies
The tallest corn (Iowa, Illinois, Nebraska) reaches ear height; the landscape ripens from green to gold-brown. Autumn storms arrive with renewed intensity.
- SWSouthwest Desert
Harvest moon over stone
September's cooler nights reveal desert species returning to nocturnal foraging.
- TRTropical / Sub-Tropical
Peak storm season dawns
September opens with peak Atlantic hurricane activity; the region faces its most intense weather window.
- AKAlaska Subarctic
Summer sun slips toward horizon
Autumn equinox approaches; daylight contracts to twelve hours, aurora visible on dark edges of twilight.
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.