Weather StoryAlmanac, microseasons, and the day's weather story.

Microseason 71 of 72 · December 21–25

Solstice — the sun begins return

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.

  1. NENortheast Continental

    Solstice — the sun begins return

    Winter solstice — the year's longest night, then light returns.

  2. SESoutheast Subtropical

    The Sun Begins its Return

    Winter solstice marks the turning point. Days now lengthen imperceptibly. The solar noon sun traces its lowest arc; shadows stretch longest; cold persists but the year's pivot is here.

  3. PNWPacific Northwest

    The sun turns at solstice

    Winter solstice: shortest day, longest night. Sunrise 7:54 AM, sunset 4:17 PM. Turnaround point. Sun angle lowest. Temperatures often mild after.

  4. CACalifornia Mediterranean

    Winter solstice: the sun turns

    Shortest day passes; weak southern sun climbs barely above the horizon by noon; rainy season enters deepest phase.

  5. MWMountain West

    Winter solstice — the sun returns

    At the solstice, the sun begins its slow climb northward. Though the deepest cold still lies ahead, light itself turns toward spring.

  6. MPPlains Continental

    Solstice — sun begins return

    Winter solstice: the year's darkest day, the sun's lowest arc. By solstice, the return begins. Cold persists, but light slowly wins.

  7. SWSouthwest Desert

    The sun turns north

    After solstice, daylight minutes slowly increase. Winter rains green the landscape briefly. Desert plants sense returning light.

  8. TRTropical / Sub-Tropical

    Solstice—renewal in stillness

    Winter solstice marks the year's turning. Days begin to lengthen. Driest period peaks. Holidays fill harbors and beaches.

  9. AKAlaska Subarctic

    The sun returns, barely perceptible

    Winter solstice passes. Days begin to lengthen, but the change is imperceptible for weeks. Darkness still dominates.

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.