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

Microseason 31 of 72 · June 1–5

Fireflies rise from the lawn

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

    Fireflies rise from the lawn

    Firefly displays begin in earnest in parks and backyards.

  2. SESoutheast Subtropical

    Fireflies pulse through the magnolias

    First fireflies emerge in soft June dusk, blinking above humid lawns and oak groves across the Piedmont and Coastal Plain.

  3. PNWPacific Northwest

    Rufous Hummingbirds Arrive

    Brilliant red males claim flowering currant and manzanita. Territorial chases spark in dawn light along the forest edge.

  4. CACalifornia Mediterranean

    Coastal fog thickens at dawn

    Marine layer settles over the coast each morning, mixing with the inland heat that will peak by afternoon.

  5. MWMountain West

    Pikas hayfeeding in granite peaks

    Alpine meadows emerge from snowmelt as marmots whistle and pikas begin caching vegetation for winter.

  6. MPPlains Continental

    Prairie lightning bugs rise

    Fireflies emerge across open grasslands and oak savanna edges, their bioluminescence visible in twilight above milkweed and clover.

  7. SWSouthwest Desert

    Heat hardens the dust

    Pre-monsoon drought intensifies — the driest week of the year. Creosote dominates in brittle browns, saguaro spines cast needle-sharp shadows. Cicadas emerge early.

  8. TRTropical / Sub-Tropical

    First trades stir the ceiba canopy

    Trade winds freshen at dawn. Plumeria crowns fill streets with fragrance. Hurricane season officially begins.

  9. AKAlaska Subarctic

    Mosquitoes rise from snowmelt

    Swarms of mosquitoes emerge from tundra pools as warming days accelerate snowmelt across the subarctic interior and coast.

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.