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

Posen, Illinois Weather

Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →

Posen weather forecast — hour by hour, 7-day outlook, NOAA radar

Posen, IL
Saturday, July 4 at 5:54 PM
74
°
Heavy Rain
Feels like
80°
Humidity
93%
Wind
6 mph
Sunrise
12:22 AM
Sunset
3:28 PM
Posen, IL
Hour by hour · 24h
24-Hour ForecastPosen, IL: 24-hour forecast. Temperatures range from 67 to 76 degrees Fahrenheit with a 79% chance of precipitation at 6 PM.
L 67°H 76°
Posen, IL
7-day forecast
  1. Today
    Jul 4
    Rain
    80%
    0.67″
    85°69°—
  2. Sunday
    Jul 5
    Overcast
    17%
    —
    76°67°-9°
  3. Monday
    Jul 6
    Overcast
    —
    —
    78°68°+2°
  4. Tuesday
    Jul 7
    Overcast
    —
    —
    87°64°+9°
  5. Wednesday
    Jul 8
    Overcast
    —
    —
    87°67°0°
  6. Thursday
    Jul 9
    Thunderstorm
    55%
    0.03″
    79°68°-8°
  7. Friday
    Jul 10
    Drizzle
    33%
    0.02″
    80°67°+1°
Posen, IL
Next 24 hours · Mild now
65°72°79°12p6p12a6anow 76°high 76°low 67°PRECIP %
Posen, IL
Anemometer · 24h winds · from true
NESW
From · True
NNW
340° · veering 151°
Direction
NNW
340°
Sustained
6
mph
Gust
15
mph
Peak 24h
19
avg 4
Beaufort · 2 · LIGHT BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 4 · pk 19 @ 5:00p
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 1910SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 151° from the nnw.
Posen, IL
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
991.8
-1.1 mb in 3h · falling · 29.29 inHg
Now
991.8
mb
3h
-1.1
mb
12h
-1.6
mb
24h
-1.5
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 991–994
9859909951000STORM|RAIN-21h-18h-15h-12h-9h-6h-3h-24hNOW994.3991.4991.6
−24h−18h−12h−6hnow
Deep low still deepening — rough seas, strong wind, persistent rain.
Posen, IL
Air quality
85
AQI
Moderate
↑+44 in 6h

AQI 85 (Moderate), driven by Ozone. AQI up 44 in the last 6 hours — air quality is degrading. Ozone at AQI 78 — peak already passed at 1 PM under overcast skies. Levels should ease through evening.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5Moderate
16.8μg/m³
PM 10Good
17μg/m³
NO₂Good
11μg/m³
OzoneDRIVERUnhealthy SG
124μg/m³
UV IndexLow
0.4

What's driving it

Ozone × UV × Sky

Ozone at AQI 78 — peak already passed at 1 PM under overcast skies. Levels should ease through evening.

Present
AQI 78
UV peak
0.3 at earlier today
Sky at peak
overcast
Projected peak
AQI 78

PM × Wind × Precip

PM scrubbed by 3 hours of recent rain — PM2.5 down to 16.8 µg/m³, PM10 to 17.4 µg/m³.

PM2.5/PM10
0.97
Wind
light
Recent rain
3h in last 6h
Pattern
washed out

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SATSUNMONTUEWEDTHUFRISAT7-DAY PM2.5 TREND · μg/m³300
Posen, IL
Sky cover · visibility · 24h
Cloud cover
100%
OVERCAST
100%0%−24h−18h−12h−6hnow
Visibility
4.1mi
MODERATE
52 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
22:54 UTC · Posen, IL · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
22:54 UTC · Posen, IL · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Posen, IL
Satellite · infrared · animated
Posen, IL
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Posen, IL
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
4:49 AM
Sunrise
12:22 AM
Daylight
15h 06m
Sunset
3:28 PM
Civil dusk
9:03 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Posen, IL
The moon
Waning Gibbous
78% illuminated
Moonrise
10:48 PM
Moonset
9:55 AM
In sign
♓︎ Pisces
Posen, IL
Microseason
Jul 1–5

Cicadas claim the afternoon

plant
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Posen at a glance

  • Today vs. normal: 4°F above the seasonal normal for this latitude
  • Last frost: April 26 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 60469

16-Day Forecast — Posen

  1. Sat85°69°80%
  2. Sun76°67°17%
  3. Mon78°68°6%
  4. Tue87°64°2%
  5. Wed87°67°5%
  6. Thu79°68°55%
  7. Fri80°67°33%
  8. Sat72°64°12%
  9. Sun81°61°9%
  10. Mon76°60°9%
  11. Tue81°61°7%
  12. Wed83°65°36%
  13. Thu87°66°31%
  14. Fri78°72°24%
  15. Sat84°69°19%
  16. Sun75°65°45%

Forecast data from Open-Meteo (CC BY 4.0).

Right now in the garden

Peak growing season

As of July 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

SPC Convective Outlook

Storm Prediction Center — Posen

SPC has placed Posen in the Marginal Risk category for severe thunderstorms today.

  • TODAYMRGLMarginal Risk
  • TOMORROWTSTMGeneral Thunderstorms
  • DAY 3NONENo severe risk

Isolated severe storms possible. Limited threat for hail or damaging wind.

Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.

January 1–5: The year turns in silence.January 6–10: Ice thickens on still water.January 11–15: Shortest shadows lengthen.January 16–20: Pheasants begin to call.January 21–25: Springs begin to thaw.January 26–31: Chickadees announce dawn.February 1–5: East wind softens the frost.February 6–10: Sap begins to rise.February 11–15: First snowdrops appear.February 16–20: Red-winged blackbirds return.February 21–25: Rain begins to replace snow.February 26–28: Skunk cabbage pushes through ice.March 1–5: Ice withdraws from the reservoir.March 6–10: Crocuses open to weak sun.March 11–15: Peepers call from the marsh.March 16–20: Woodcocks spiral at dusk.March 21–25: Equinox — light overtakes dark.March 26–31: Forsythia opens along the fences.April 1–5: Cherry blossoms drift like snow.April 6–10: Warblers appear in the understory.April 11–15: Magnolias bloom and fall in a day.April 16–20: Dogwoods float above the forest.April 21–25: Lilacs perfume the evening.April 26–30: Last frost releases the garden.May 1–5: Warblers flood the Ramble.May 6–10: Tulip poplars light their candles.May 11–15: Shad run up the rivers.May 16–20: Roses open along the stoops.May 21–25: Firefly scouts appear at dusk.May 26–31: Strawberries ripen in the sun.June 1–5: Fireflies rise from the lawn.June 6–10: Elderflowers open in hedgerows.June 11–15: Solstice approaches — longest light.June 16–20: Honeysuckle sweetens the night.June 21–25: Solstice — the sun stands still.June 26–30: Lightning bugs drift through oaks.July 1–5: Cicadas claim the afternoon.July 6–10: Queen Anne's lace lines the roads.July 11–15: Thunder builds each afternoon.July 16–20: Corn reaches for the tassels.July 21–25: Dog days settle in the haze.July 26–31: Katydids begin their chorus.August 1–5: Night falls a minute earlier.August 6–10: Sunflowers face the morning.August 11–15: Goldenrod begins to bloom.August 16–20: Crickets pulse through warm nights.August 21–25: First cool morning surprises.August 26–31: Monarchs stage for flight.September 1–5: School buses reappear.September 6–10: Asters purple the roadsides.September 11–15: Hawk migration over the Hudson.September 16–20: Equinox — dark overtakes light.September 21–25: Apples hang heavy on the branch.September 26–30: Geese begin to chevron south.October 1–5: Witch hazel blooms as others fade.October 6–10: Maples begin to blaze.October 11–15: Frost paints the garden black.October 16–20: Oaks turn bronze and russet.October 21–25: Leaves rattle down the gutters.October 26–31: Clocks fall back — dusk at five.November 1–5: Ginkgos drop overnight.November 6–10: Last leaves cling stubbornly.November 11–15: Juncos arrive from the north.November 16–20: Bare branches reveal the sky.November 21–25: First flurries dust the rooftops.November 26–30: Woodsmoke curls through the block.December 1–5: Darkness settles before dinner.December 6–10: Holly and winterberry persist.December 11–15: Shortest day approaches.December 16–20: Ice begins to form at the edges.December 21–25: Solstice — the sun begins return.December 26–31: The year turns in silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · July 1–5

Cicadas claim the afternoon

Annual cicada buzz begins, peaking in the heat of the day.

Day 185 of 365 · Wedge 37 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
Aprillettuce, peas, spinach, radishes—
Maylettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Junetomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
August—tomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Octoberfall brassicas, garlic (overwinter), carrotswinter squash, tomatoes (last)
November——
December——

A year in weather

The year in Posen tops out in July (~76°F) and dips lowest in January (~24°F), with May wettest at 4.2 inches and January driest at 2.0 inches.

MonthMean tempPrecipRainy days
January24°2.0″16
February27°2.1″14
March37°3.0″16
April50°3.8″17
May59°4.2″18
June70°4.0″17
July76°2.9″15
August75°3.0″14
September68°3.1″14
October55°3.0″13
November40°3.2″16
December28°2.5″15

Regional context

Drawing on NOAA NCEI 1991-2020 normals, Posen's January averages 24°F and July 76°F — 53°F apart — while precipitation totals roughly 36.8 inches over some 184 days.

Posen's precipitation spreads evenly: May peaks at 4.2 inches on 18.2 wet days, while January holds 2.0 inches over 15.7 — no month dominates Posen's rain calendar. That even rhythm groups Posen with places like Dixmoor, IL, Robbins, IL and Midlothian, IL.

By mid-April the frosts ease in Posen, opening the season for kale, peas, spinach, and parsnips. Warm-soil crops in Posen wait about two weeks past Posen's last frost, once the soil warms. It shuts near mid-November, when freezes return to Posen and tender plants need cover. In Posen, low spots run 4-7°F colder than nearby slopes, nudging Posen's frost dates a week.

Similar climates: Dixmoor, IL, Robbins, IL, Midlothian, IL, Blue Island, IL, Markham, IL.

Frequently asked

When does it freeze in Posen?
Posen's last spring frost lands near mid-April, and in Posen the first fall frost follows around mid-November.
What is the rainy season in Posen?
Rainfall in Posen peaks in May near 4.2 inches, out of about 37 inches annually.
What is the warmest month in Posen?
July is Posen's warmest month, averaging about 76°F.
What is the coldest month in Posen?
Posen bottoms out in January, with a mean near 24°F.
When can I start a vegetable garden in Posen?
Posen's last frost (mid-April) cues hardy greens; in Posen, hold heat-lovers two weeks past.
How many rainy days does Posen get?
Posen averages about 184 days with measurable rain or snow each year.
What hardiness zone is Posen?
Posen's USDA zone comes from its January mean (24°F); enter the ZIP on the USDA lookup for the number.
What is the 10-day forecast for Posen?
Posen's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in Posen?
See this week's day-by-day rain chances for Posen in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Posen?
Current conditions for Posen and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Posen forecast updated?
The Posen forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Posen?
Today's sunrise and sunset times for Posen are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for Posen?
The next few days in Posen's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

Posen, Illinois has a warm-summer humid continental climate: January averages roughly 24°F, July about 76°F, 52°F between them.

In a typical year Posen records about 37 inches of precipitation on around 184 days.

Latitude 41.6°N gives Posen its 52°F swing, and with it the rhythm of Posen's growing season.

All cities in Illinois →

Oak Lawn, IL weather →

ZIP codes in Posen

  • 60469

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.