Pennsylvania Nature Guide: December 2026
Data updated: August 2026Sources & method · Corrections
December settles Pennsylvania into winter — bare woods and snow on the ridges, the Christmas Bird Count season in full swing, waterfowl crowding the open rivers, and the brilliant Geminid meteor shower and winter constellations blazing over the longest nights of the year.
Week by week in December
December 3–9
- The Christmas Bird Count season opens — waterfowl crowd the open Susquehanna with mergansers, goldeneye, and wintering eagles.
- Winterberry holly glows red in the wetlands and American holly holds its green and berries in the winter woods.
- Fresh evergreen wreaths, holly, and Christmas trees join the storage crops and Kennett Square mushrooms at the markets.
December 10–16
- The Geminid meteor shower peaks around December 14 — up to 100 an hour, the richest, most reliable shower of the year.
- Bald eagles and rafts of diving ducks concentrate on the open rivers, with the famous eagle show holding at Conowingo.
- The dark eastern hemlock, the state tree, shades the snowy gorges as the bare deciduous woods rest.
December 17–23
- The winter solstice near the 21st brings the longest night, and brilliant Orion and the Winter Hexagon rule the dark sky.
- Feeders bustle with cardinals, chickadees, titmice, and juncos as the ruffed grouse, the state bird, holds tight in the laurel.
- Mourning cloaks overwinter as adults behind bark and in woodpiles, protected by natural antifreeze against the deep cold.
December 24–31
- Winter birding holds steady — eagles and diving ducks on the open water while feeders draw the hardy resident flock.
- The Winter Hexagon and brilliant Orion blaze through the long, frigid nights, closing the year under the clearest skies of the season.
- The bare sycamores, shaggy hickories, and dark hemlocks stand against the snow as the woods settle into their winter rest.
Birds This Month
December is the start of winter birding and the heart of the Christmas Bird Count season, when volunteers across Pennsylvania fan out to tally the winter avifauna. The waterfowl are the spectacle: wherever the Susquehanna, Delaware, and Allegheny rivers stay open, rafts of common and hooded mergansers, common goldeneye, canvasback, scaup, and ruddy ducks gather, watched over by wintering bald eagles — Conowingo Dam, just over the Maryland line on the lower Susquehanna, draws eagles and gulls in famous numbers within easy reach of the southeast.
The winter land birds are settled in: feeders bustle with northern cardinals, black-capped chickadees, tufted titmice, white-breasted nuthatches, dark-eyed juncos, and downy and red-bellied woodpeckers. In open farm country and on the Lake Erie plain, watch for rough-legged hawks, northern harriers, short-eared owls, and a possible snowy owl. In an irruption winter, pine siskins, common redpolls, or evening grosbeaks push south. The state bird, the ruffed grouse, holds tight in the dense young woods and laurel.
What's Blooming
December has no wildflowers in Pennsylvania's frozen, snow-covered landscape, but the winter fields keep their stark architecture. The dried seed-heads of goldenrod, aster, coneflower, black-eyed Susan, and joe-pye weed stand brown above the snow, the flat umbels of Queen Anne's lace hold their shape, and the last milkweed pods release their silk on the cold wind — all of it food and shelter for wintering finches, sparrows, and dormant insects.
In the woods, the evergreen ground plants carry the only living color beneath the snow: the leathery, red-berried wintergreen (teaberry), the trailing partridgeberry, and the deep-green Christmas fern, whose fronds were traditionally cut for holiday decoration. The native American holly and the conifers hold their green, and the bright red berries of winterberry holly glow in the wetlands. In the mildest southeastern gardens, a winter-blooming witch hazel or the first snowdrop might surprise during a December thaw, but the wildflower year is otherwise at rest.
Garden This Month
December begins Pennsylvania's gardening off-season, when there is little to do outdoors but rest and plan. Across most of the state the ground is frozen and snow-covered. The main outdoor jobs are protective: let snow accumulate over perennial beds as insulation, gently brush heavy, wet snow off evergreens and shrubs to prevent breakage, and check that mulch and tree wrap still guard tender roots and young bark against the cold and hungry rodents and deer.
This is the season for indoor work and forward planning. Review the past year's garden — what thrived, what failed — and begin browsing seed catalogs, ordering early for the popular and short-season varieties. Force paperwhites and amaryllis for indoor winter color, tend houseplants in the low light, and clean, sharpen, and oil tools for spring. Keep the bird feeders full — a garden that feeds the winter birds is repaid in spring pest control. Otherwise, let the garden sleep through the year's shortest, darkest days.
Zone 5a (northern tier & Pocono highlands): the garden is locked in deep snow and cold. Let the snow insulate the beds, knock heavy snow off evergreens to prevent breakage, and turn to seed catalogs and next year's plan.
Zone 6a (ridge-and-valley & central uplands): the ground freezes and dormancy sets in. Mulch is in place; check tree wrap against rodents, brush snow off shrubs, and spend the dark month planning and ordering seeds.
Zone 7a (southeastern Piedmont): the mildest corner. Cold frames and heavy mulch can still hold hardy greens, and you can prune dormant shade trees on mild days, but protect tender plants from the sharpest cold snaps.
What's at the Farmers Market
December markets lean fully on the storage harvest and the holiday table. The stands and winter markets carry storage apples from Adams County, potatoes, sweet potatoes, onions, garlic, leeks, cabbage, Brussels sprouts, carrots, beets, parsnips, turnips, and winter squash from the root cellar, plus cold-stored and high-tunnel kale, spinach, and greens.
Pennsylvania's Kennett Square mushrooms are a holiday staple, abundant and fresh all winter, and the stands fill with maple syrup, honey, cheeses, eggs, apple cider, and value-added goods, plus fresh evergreen wreaths, holly, and Christmas trees from the state's many tree farms. Choose firm, heavy storage apples and squash with hard rinds; keep roots cold and humid in the cellar; and select mushrooms with firm, dry caps, storing them unwashed in a paper bag in the fridge. Fresh local produce is scarce now, so the storage crops and greenhouse greens carry the table until spring.
Night Sky This Month
December's long, dark nights around the winter solstice near the 21st deliver the year's best stargazing, crowned by the Geminid meteor shower, which peaks around December 14 with up to 100 or more meteors per hour — the richest, most reliable shower of the year. Bundle up and watch the slow, bright Geminids stream from near the twins of Gemini, best from late evening through the small hours at a dark site like Cherry Springs State Park.
The brilliant winter constellations rule the long nights: Orion strides up the south, his belt pointing to dazzling Sirius, and the great Winter Hexagon of Sirius, Procyon, Pollux, Capella, Aldebaran, and Rigel wheels across the sky, with the Pleiades riding high and the Orion Nebula glowing in binoculars. The minor Ursid shower follows near the solstice. The printable Pennsylvania night-sky guide lists this year's exact Geminid peak, planet positions, and the best dark-sky sites near you for the cold, clear December nights.
Butterflies & Pollinators
December finds Pennsylvania's butterflies entirely dormant, hidden all around the winter landscape. Mourning cloaks and eastern commas overwinter as adults, tucked deep behind loose bark, in woodpiles, and in unheated sheds, their bodies protected by natural antifreeze compounds against the deep cold; they will be the first butterflies to fly again on a warm late-winter day.
Every other species passes the winter in an earlier stage. Monarchs are now clustered by the millions in the high oyamel-fir forests of central Mexico, having completed their great migration south. Back in Pennsylvania, the great spangled fritillary waits as a tiny unfed caterpillar in the leaf litter, the eastern tiger and spicebush swallowtails as chrysalises camouflaged on twigs, and many skippers and whites as eggs or larvae among the standing stems. The undisturbed leaf litter, hollow stems, and brush piles of a winter garden are full of next summer's butterflies, quietly waiting out the cold.
What to plant for them is in the Pennsylvania native plants guide
Trees This Month
December reveals Pennsylvania's forests in full winter form, the deciduous trees bare against the snow except for the marcescent American beech and young oaks, which hold their pale, papery leaves through the cold. This is the season to read the woods by bark and silhouette — the shaggy shagbark hickory, the smooth gray beech, the broken-plate black cherry, and the ghostly white limbs of the sycamore along the frozen streams.
The conifers carry the only green and define the winter landscape: the dark eastern hemlock, the state tree, shading the gorges and cool ravines; the soft five-needled eastern white pine on the slopes; and the red spruce and balsam fir on the high Pocono and northern-tier ridges. The native American holly holds its glossy green leaves and red berries, and the wetland winterberry glows red — both gathered for the holidays alongside the state's farmed Christmas trees. Every twig's buds are set and waiting, the dormant promise of the spring to come.
The Pennsylvania native plants guide covers what grows with them
Weather & Daylight
Across Pennsylvania, a typical December day averages a high near 39°F and a low near 24°F, with about 3.5 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Winter returns in earnest, short cold days hover near freezing and nights are frigid, with snow and rain both likely.
| Average high | 39°F |
|---|---|
| Average low | 24°F |
| Precipitation | 3.5 in |
| Sunrise (mid-month) | 7:27 ET |
| Sunset (mid-month) | 16:45 ET |
Figures are statewide averages over the 1991–2020 U.S. climate normals; local conditions vary with elevation and distance from the coast. Sunrise and sunset are computed for a midstate point on the 15th (ET).
Next month's version of this page, by email
One short note when Pennsylvania's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Pennsylvania guides
The complete Pennsylvania birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: December in Rhode Island · December in South Carolina · December in South Dakota