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

Microseason 39 of 72 · July 11–15

Thunder builds each afternoon

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

    Thunder builds each afternoon

    Sea-breeze convergence triggers daily convective storms.

  2. SESoutheast Subtropical

    Thunder builds each drowsy afternoon

    July's height: thunderstorms arrive like clockwork each day, flooding the Piedmont and Coastal Plain with deluges.

  3. PNWPacific Northwest

    Red Huckleberry Ripens

    Translucent red berries cluster thickly on drooping branches in moist draws. Bears move into berry-rich creek bottoms; ravens follow to cache surplus.

  4. CACalifornia Mediterranean

    Pacific high settles in firmly

    The subtropical high-pressure dome locks over California; coastal fog intensifies while inland heat escalates.

  5. MWMountain West

    Lightning crowns every peak

    Peak monsoon intensity; daily thunderstorms build reliably over alpine summits, bringing spectacular lightning and brief torrential rain.

  6. MPPlains Continental

    Thunder builds every afternoon

    July's heat and humidity peak; towering cumulus clouds build daily over the plains, spawning severe thunderstorms, hail, and occasional tornadoes.

  7. SWSouthwest Desert

    The lightning oracle speaks

    Peak monsoon violence. Cloud tops tower 50,000 feet. Lightning frequency reaches one strike per second within visible range. Hail and flash floods carve new arroyos.

  8. TRTropical / Sub-Tropical

    Storm surge begins its rhythm

    Afternoon thunderheads tower to 50,000 feet. Downbursts shake mangrove canopies. Tidal surges pool freshwater inland. Breeding cycles accelerate.

  9. AKAlaska Subarctic

    Thunderstorms gather on summer peaks

    Afternoon convection develops into brief, intense Pacific-fed storms that drench coastal ranges and interior valleys.

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.