Chicakō.xlsx

	A	B	C	D	E	F
1	#	Dates	Short Name	Detailed Description	Marker Type	Confidence
2	1	Jan 1–5	Shelf ice breathes	Near-shore 'shelf ice' begins to form in jagged, jostling plates along Lake Michigan during sustained cold snaps.	Water/Weather	Medium
3	2	Jan 6–10	Owls claim the night	Great horned owls establish territories; evening duets are audible in forest preserves and large parks.	Animal	High
4	3	Jan 11–15	Rabbit maps on snow	Fresh cottontail tracks stitch across alleys, yards, and prairie paths after light snowfalls.	Animal	High
5	4	Jan 16–20	Thaw, drip, refreeze	Freeze–thaw cycles create midday meltwater and overnight black ice on sidewalks and curbs.	Weather	High
6	5	Jan 21–25	Lake-effect whispers	Narrow snow bands sweep in off the lake, dusting parts of the city while others stay clear.	Weather	Medium
7	6	Jan 26–30	Sun lifts a little higher	Noticeably longer afternoons bring crisp blue skies on cold, dry days.	Weather	High
8	7	Jan 31–Feb 4	First south-wind breath	A brief mild spell softens plow piles; gutters run and the lake darkens along the edge.	Weather	Medium
9	8	Feb 5–9	Snowdrops tip the soil	In protected city beds, early bulbs like snowdrops and hellebores emerge through leaf litter.	Plant	Medium
10	9	Feb 10–14	Coyote chorus	Breeding-season yips and yowls carry at night; occasional daytime sightings near rail corridors.	Animal	High
11	10	Feb 15–19	Sap stirs on warm days	Maples begin to weep during daytime thaws; taps in regional sugarbushes start to run.	Plant	Medium
12	11	Feb 20–24	Red‑winged scouts return	Male red‑winged blackbirds stake early claims in cattail marshes with bold calls.	Animal	High
13	12	Feb 25–Mar 1	Lagoon ice loosens	Cracks lace across park lagoons; dark leads open near shore and under bridges.	Water/Weather	High
14	13	Mar 2–6	Crocuses pop	Crocuses and early iris bring the first splashes of color to south‑facing lawns and parkways.	Plant	High
15	14	Mar 7–11	First rumbles	Clippers give way to early thunderstorms; brief lightning and graupel are possible.	Weather	Medium
16	15	Mar 12–16	Mud season	Freeze‑thaw and snowmelt saturate trails; dog parks and prairie soils turn to soup.	Weather/Soil	High
17	16	Mar 17–21	Chorus frogs ring	Western chorus frogs and spring peepers trill at dusk in ditches and wet prairies.	Animal	Medium
18	17	Mar 22–26	Silver maples dust the air	Tiny red flowers open; pollen drifts lightly from maples and elms.	Plant	High
19	18	Mar 27–31	Prairie burn smoke	Restoration crews conduct prescribed burns; thin smoke and blackened fields appear.	Human/Natural	High
20	19	Apr 1–5	Daffodils nod	Boulevards and median beds brighten with daffodils and hyacinths.	Plant	High
21	20	Apr 6–10	Tree pollen wave I	Maple, elm, and oak pollen coat cars overnight; allergy season begins in earnest.	Plant	High
22	21	Apr 11–15	Frost’s last feint	A late frost remains possible; gardeners watch forecasts and cover tender starts.	Weather	Medium
23	22	Apr 16–20	Ephemerals carpet woods	Trout lily, spring beauty, and bloodroot carpet oak woodlands before leaf‑out.	Plant	High
24	23	Apr 21–25	Crabapples set buds	Crabapples swell and blush; bees begin to work early blossoms on warm afternoons.	Plant	High
25	24	Apr 26–30	First warbler scouts	Early warblers flick through lakefront trees; birders scan hedgerows at dawn.	Animal	High
26	25	May 1–5	Lilacs perfume blocks	Classic Chicago scent: lilac clusters open, drawing bumblebees and nostalgia alike.	Plant	High
27	26	May 6–10	Blossom storm	Apples and crabapples release petal ‘snow’; sidewalks drift in pink and white.	Plant	High
28	27	May 11–15	Cottonwoods tassel	Male catkins dangle and shed; nearby sidewalks gather rust‑brown sheds.	Plant	High
29	28	May 16–20	Thunder alley	Humid air fuels repeated downpours; first tropic‑feeling nights arrive.	Weather	Medium
30	29	May 21–25	Cottonwood fluff floats	Female cottonwoods release seed fluff that gathers in gutters and fence corners.	Plant	High
31	30	May 26–30	Dragonflies on patrol	Common green darners and other dragonflies hawk over ponds and lawns, munching mosquitoes.	Animal	High
32	31	May 31–Jun 4	Peonies & iris parade	Heavy, rain‑tipping peonies and iris dominate gardens; ants explore peony buds.	Plant	High
33	32	Jun 5–9	Milkweed buds swell	Common milkweed forms tight bud clusters; first monarch eggs appear soon after.	Plant	High
34	33	Jun 10–14	First fireflies	Evening sparks begin across lawns and prairies, especially after warm, wet springs.	Animal	High
35	34	Jun 15–19	Firefly peak	Synchronous displays in dark spots; activity surges on warm, still nights.	Animal	High
36	35	Jun 20–24	Monarch nurseries	Milkweed hosts monarch eggs and tiny caterpillars; kids search undersides of leaves.	Animal/Plant	High
37	36	Jun 25–29	Lake breeze machine	Onshore flow cools the lakefront in afternoons while inland neighborhoods stay hot.	Weather	High
38	37	Jun 30–Jul 4	Heat, boom, plume	First true heat wave; towering cumulus, fireworks haze, and evening cicada buzz begin.	Weather/Animal	Medium
39	38	Jul 5–9	Dog‑day cicadas start	Annual cicadas drone from trees in daylight; molted shells appear on trunks.	Animal	High
40	39	Jul 10–14	Prairie fireworks	Purple coneflower, black‑eyed Susan, and wild bergamot color tallgrass restorations.	Plant	High
41	40	Jul 15–19	Sweet corn arrives	Farm markets brim with local ears; corn scent carries on hot afternoons.	Human/Natural	High
42	41	Jul 20–24	Swift hour	Chimney swifts scythe the sky at dusk over schools and factories, chittering as they circle.	Animal	High
43	42	Jul 25–29	Bath‑warm shallows	Near‑shore lake temperatures peak; waders and swimmers crowd calm mornings.	Water/Weather	Medium
44	43	Jul 30–Aug 3	Haze & meteors	Humid haze softens horizons; early Perseid meteors scratch the night.	Sky/Weather	Medium
45	44	Aug 4–8	Tallgrass towers	Joe‑Pye weed, compass plant, and blazing star rise head‑high along prairie paths.	Plant	High
46	45	Aug 9–13	Perseids peak	Best meteor viewing on clear nights away from city lights; crickets provide the soundtrack.	Sky/Animal	High
47	46	Aug 14–18	Goldenrod lights fields	Goldenrod species ignite roadsides and prairies; pollinators teem on sunny days.	Plant	High
48	47	Aug 19–23	Ragweed wakes	Ragweed pollen surges and dominates late‑summer allergies until hard frost.	Plant	High
49	48	Aug 24–28	Southbound shorebirds	Sandpipers and yellowlegs work exposed mud along the lakefront and inland ponds.	Animal	Medium
50	49	Aug 29–Sep 2	Cricket nights	Evening soundscape shifts to steady field‑cricket chirr and katydid rasps.	Animal	High
51	50	Sep 3–7	Monarch river begins	Monarchs stream southwest, nectaring on asters and goldenrod along flyways.	Animal	High
52	51	Sep 8–12	Sumac goes scarlet	Staghorn sumac and Virginia creeper blaze red along rail embankments and edges.	Plant	High
53	52	Sep 13–17	Orchard heavy	Regional orchards hit stride with apples and pears; yellow jackets gather near drops.	Human/Natural	High
54	53	Sep 18–22	Equinox balance	Day and night nearly equal; first cool snaps nudge trees toward change.	Sky/Weather	High
55	54	Sep 23–27	Hummers on the wing	Ruby‑throated hummingbirds tank up at salvias and feeders; most depart by early October.	Animal	High
56	55	Sep 28–Oct 2	Goldenrod finale	Late species carry the banner as others fade; pollinator traffic remains high on warm days.	Plant	High
57	56	Oct 3–7	Ragweed’s last stand	Ragweed remains troublesome until the first hard frost knocks it back.	Plant	High
58	57	Oct 8–12	Frost watch	Patchy frost appears in low spots; gardeners cover late tomatoes and peppers.	Weather	Medium
59	58	Oct 13–17	Maples start to flame	Norway and red maples shift through oranges and reds; sugar maples glow in preserves.	Plant	High
60	59	Oct 18–22	First freeze (typ.)	Average first freeze near this window; tender annuals blacken overnight.	Weather	High
61	60	Oct 23–27	Color peak drifts cityward	Best urban color often arrives late Oct into early Nov, with oaks lagging.	Plant	Medium
62	61	Oct 28–Nov 1	Leaf‑fall lanes	Windy days send leaves streaming; piles gather along curbs and fences.	Weather/Plant	High
63	62	Nov 2–6	First flurries	Cold rain mixes with snow; brief bursts whiten grass before melting.	Weather	High
64	63	Nov 7–11	Waterfowl highways	Diving ducks, geese, and swans stage on open water along the lakefront and lagoons.	Animal	High
65	64	Nov 12–16	Ginkgo gold drop	Ginkgoes often shed en masse after the season’s first sharp cold night—sidewalks turn gold.	Plant	High
66	65	Nov 17–21	Lake‑effect ceilings	Persistent gray stratus and drizzle develop under cold NE winds off the lake.	Weather	Medium
67	66	Nov 22–26	Final acorn frenzy	Squirrels finish caching acorns and walnuts; gnawed shells litter stump tops.	Animal	High
68	67	Nov 27–Dec 1	First measurable snow (typ.)	Many years see the first measurable snowfall in this window, though it varies widely.	Weather	Medium
69	68	Dec 2–6	Harbor skim ice	Protected harbors and ponds glaze over on calm, cold nights before breaking by afternoon sun.	Water/Weather	High
70	69	Dec 7–11	Owl courtship begins	Great horned owls become more vocal as courtship ramps up heading into winter.	Animal	High
71	70	Dec 12–16	Winter ducks on open water	Goldeneye and mergansers sparkle on Lake Michigan and larger lagoons.	Animal	High
72	71	Dec 17–21	Solstice sun dogs	Low sun angles and ice crystals produce halos and sun dogs on the coldest mornings.	Sky/Weather	Medium
73	72	Dec 22–31	Deep‑freeze windows	Arctic shots consolidate shelf ice and stiffen soils; the city settles into true winter.	Weather/Water	Medium
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