Microseason 24 of 72 · April 26–30
Last frost releases the garden
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
Last frost releases the garden
Zone 7b last frost date — safe to transplant tender seedlings.
- SESoutheast Subtropical
Frost retreats; seedlings rise free
Last frost passes by late April across most of the SE. Gardens surge. Tropical annuals find safety.
- PNWPacific Northwest
Frost Releases the Garden
Last frost date arrives on lowlands (mid-April); tender plants and annuals now safe from freezing. Trillium and fawn lily carpet the forest floor in white and pale yellow.
- CACalifornia Mediterranean
Chaparral awakens after spring rains
Chamise, sage, and ceanothus thicken with new foliage. Bobcats and gray foxes hunt. Interior temperatures climb above 80°F; coastal fog thickens.
- MWMountain West
Last frost yields to summer growth
Late spring frost windows close as alpine meadows accelerate growth. Pronghorn fawns are born across the sage and grassland.
- MPPlains Continental
Last Frost Retreats North
The killing frost date passes (late April south, early May north); warm-season planting begins in earnest.
- SWSouthwest Desert
Last frost recedes to memory
Nighttime lows stay above freezing; frost danger ends across low desert.
- TRTropical / Sub-Tropical
Heat breaks the last restraint
Temperatures climb into the 85–90s; afternoon showers cool the islands briefly. Wet season fully established. Frost is forgotten.
- AKAlaska Subarctic
The land drinks deep
Frost no longer locks the soil at night in valleys; snowmelt floods streams. Permafrost thaw begins; ground becomes boggy and soft.
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.