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Chatham, Illinois Weather

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

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

Chatham, IL
Saturday, July 4 at 10:53 AM
86
°
Clear
Feels like
94°
Humidity
65%
Wind
10 mph
Sunrise
12:36 AM
Sunset
3:29 PM
Chatham, IL
Hour by hour · 24h
24-Hour ForecastChatham, IL: 24-hour forecast. Temperatures range from 71 to 92 degrees Fahrenheit with a 24% chance of precipitation at 3 PM.
L 71°H 92°
Chatham, IL
7-day forecast
  1. Today
    Jul 4
    Light Drizzle
    39%
    0.01″
    92°71°—
  2. Sunday
    Jul 5
    Overcast
    17%
    —
    84°71°-8°
  3. Monday
    Jul 6
    Light Drizzle
    —
    —
    84°68°0°
  4. Tuesday
    Jul 7
    Partly Cloudy
    —
    —
    81°63°-3°
  5. Wednesday
    Jul 8
    Overcast
    —
    —
    85°64°+4°
  6. Thursday
    Jul 9
    Drizzle
    41%
    0.02″
    84°71°-1°
  7. Friday
    Jul 10
    Drizzle
    41%
    0.07″
    82°70°-2°
Chatham, IL
Next 24 hours · Warm now
HOT 90°66°81°96°6a12p6p12anow 84°high 92°low 71°PRECIP %
Chatham, IL
Anemometer · 24h winds · from true
NESW
From · True
SW
229° · veering 25°
Direction
SW
229°
Sustained
10
mph
Gust
14
mph
Peak 24h
19
avg 9
Beaufort · 3 · GENTLE 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 9 · pk 19 @ 3:00p
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 185SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 25° from the sw.
Chatham, IL
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
994.4
+1.1 mb in 3h · rising · 29.36 inHg
Now
994.4
mb
3h
+1.1
mb
12h
+0.4
mb
24h
-2.5
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 994–998
9859909951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW997.5993.6995.0
−24h−18h−12h−6hnow
The low is filling — pressure climbing out of storm territory.
Chatham, IL
Air quality
28
AQI
Good
→-4 in 6h▲Peak ~43 @ 10 PM

AQI 28 (Good), driven by Ozone. AQI flat over the last 6 hours (within ±4 points). Ozone at AQI 37. Overcast through the UV peak window (cloud cover ~63%) — afternoon ozone should stay flat.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 10 PM.

PM 2.5Good
6.1μg/m³
PM 10Good
7μg/m³
NO₂Good
3μg/m³
OzoneDRIVERModerate
79μg/m³
UV IndexModerate
3.9

What's driving it

Ozone × UV × Sky

Ozone at AQI 37. Overcast through the UV peak window (cloud cover ~63%) — afternoon ozone should stay flat.

Present
AQI 37
UV peak
5.5 at 1 PM
Sky at peak
overcast
Projected peak
AQI 14

PM × Wind × Precip

PM2.5 at 6.1 µg/m³, PM10 at 6.7 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.91
Wind
breezy
Recent rain
0h in last 6h
Pattern
background

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
Chatham, IL
Sky cover · visibility · 24h
Cloud cover
6%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
51.8mi
UNLIMITED
68 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
15:53 UTC · Chatham, 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
15:53 UTC · Chatham, IL · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Chatham, IL
Satellite · infrared · animated
Chatham, IL
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Chatham, IL
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:05 AM
Sunrise
12:36 AM
Daylight
14h 53m
Sunset
3:29 PM
Civil dusk
9:03 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Chatham, IL
The moon
Waning Gibbous
80% illuminated
Moonrise
10:53 PM
Moonset
10:05 AM
In sign
♓︎ Pisces
Chatham, IL
Microseason
Jul 1–5

Cicadas claim the scorching afternoon

bird
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Chatham at a glance

  • Today vs. normal: 14°F above the seasonal normal for this latitude
  • Last frost: April 14 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 62629

16-Day Forecast — Chatham

  1. Sat92°71°39%
  2. Sun84°71°17%
  3. Mon84°68°8%
  4. Tue81°63°4%
  5. Wed85°64°8%
  6. Thu84°71°41%
  7. Fri82°70°41%
  8. Sat83°68°24%
  9. Sun74°59°5%
  10. Mon73°57°5%
  11. Tue75°60°10%
  12. Wed79°63°10%
  13. Thu82°65°16%
  14. Fri82°68°23%
  15. Sat86°71°20%
  16. Sun86°72°29%

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 — Chatham

SPC has placed Chatham in the Slight Risk category for severe thunderstorms today.

  • TODAYSLGTSlight Risk
  • TOMORROWTSTMGeneral Thunderstorms
  • DAY 3TSTMGeneral Thunderstorms

Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.

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: Frost quiets the live oaks.January 6–10: Still water thickens with ice.January 11–15: Springs begin to move beneath ice.January 16–20: Cardinal dawn calls grow bolder.January 21–25: Late January thaw pulses.January 26–31: Last freeze locks the land.February 1–5: February's lengthening light.February 6–10: Warming winds thaw the margin.February 11–15: Magnolia blooms break the gray.February 16–20: Mockingbirds resume the dawn chorus.February 21–25: Rain replaces the last snow.February 26–28: Mist clings to greening valleys.March 1–5: The green pulse awakens.March 6–10: Hibernators emerge to call.March 11–15: Dogwood and redbud ignite.March 16–20: Swallowtails emerge from winter silk.March 21–25: Light crowns the dogwood canopy.March 26–31: Redbud cascades over the thaw.April 1–5: Thunder announces the wet season.April 6–10: Barn swallows carve the warming sky.April 11–15: Magnolia blooms and falls in a breath.April 16–20: First rainbows arch over thunderheads.April 21–25: Reeds push through marsh water.April 26–30: Frost retreats; seedlings rise free.May 1–5: Warblers flood the canopy in waves.May 6–10: Tulip poplar lights the forest crown.May 11–15: Shad pulse upstream through rapids.May 16–20: Roses open on the Piedmont edge.May 21–25: Fireflies scout the humid dusk.May 26–31: Frog choruses rise from every wetland.June 1–5: Fireflies pulse through the magnolias.June 6–10: Kudzu climbs deeper into green.June 11–15: Sun climbs to its northern throne.June 16–20: Heat settles and the rain begins.June 21–25: The longest day turns toward shadow.June 26–30: Fireflies drift through Spanish moss.July 1–5: Cicadas claim the scorching afternoon.July 6–10: Thunderheads boil and break at dusk.July 11–15: Thunder builds each drowsy afternoon.July 16–20: Cicadas claim the long noon.July 21–25: Dog days drape the earth in haze.July 26–31: Katydids begin their rasping chorus.August 1–5: Dusk arrives one minute earlier each night.August 6–10: Meteorological summer's turning page.August 11–15: Cool winds gather at the margins.August 16–20: Dog-day cicadas rise.August 21–25: Heat breaks in creek beds.August 26–31: Monarchs gather strength.September 1–5: Harvests begin in earnest.September 6–10: Dew beads on resurrection fern.September 11–15: Raptors trail the thermals.September 16–20: Day and dark find balance.September 21–25: Thunder quiets the land.September 26–30: Insects retreat below.October 1–5: Swamp waters recede.October 6–10: Maples ignite the ridge.October 11–15: Asters crown the meadows.October 16–20: Crickets sing at dusk.October 21–25: Frost paints the garden.October 26–31: Light rains whisper down.November 1–5: Sweetgum Turns Crimson.November 6–10: Camellia Blooms Break Through.November 11–15: Earth Stiffens Underfoot.November 16–20: Bare Limbs Hold the Light.November 21–25: First Frost Grips the High Ground.November 26–30: North Wind Strips the Last Leaves.December 1–5: Darkness Falls Before Dinner.December 6–10: Winter Locks the Land.December 11–15: Wildlife Retreats to Shelter.December 16–20: Ice Edges Deepen Inward.December 21–25: The Sun Begins its 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 scorching afternoon

Dog-day cicadas emerge in waves, their rasp dominating every sunny hour; heat peaks above 90 degrees daily.

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

Chatham peaks at about 78°F in July and bottoms near 27°F in January; May brings the heaviest rain (4.5 inches) and January the least (1.9 inches).

MonthMean tempPrecipRainy days
January27°1.9″14
February31°2.1″12
March42°3.4″16
April54°4.1″16
May64°4.5″17
June73°4.3″15
July78°2.9″14
August78°2.5″13
September71°2.9″12
October58°3.0″11
November43°3.4″12
December31°2.7″13

Regional context

Per NOAA NCEI 1991-2020 normals, Chatham runs from a 27°F January mean to 78°F in July, a 51°F seasonal spread, with near 37.7 inches of precipitation across about 165 wet days.

Chatham's precipitation spreads evenly: May peaks at 4.5 inches on 17.0 wet days, while January holds 1.9 inches over 13.7 — no month dominates Chatham's rain calendar. It is a balanced pattern Chatham shares with places like Southern View, IL, Curran, IL and Jerome, IL.

Chatham reaches its last hard frost near mid-April; that is the cue for kale, peas, spinach, and parsnips. Chatham's heat-lovers — tomatoes, peppers, squash — hold off until Chatham's frost risk clears, 10-14 days on. The season ends by mid-November in Chatham, once hard frosts set back in. A creek-bottom lot in Chatham can lag Chatham's last frost 7-10 days behind a south slope.

Similar climates: Southern View, IL, Curran, IL, Jerome, IL, Springfield, IL, Auburn, IL.

Frequently asked

When does it freeze in Chatham?
Chatham's last spring frost lands near mid-April, and in Chatham the first fall frost follows around mid-November.
What is the rainy season in Chatham?
May is the wettest month in Chatham, about 4.5 inches on average; the year totals roughly 38 inches.
What is the warmest month in Chatham?
On average July tops the year in Chatham at about 78°F.
What is the coldest month in Chatham?
The coldest stretch in Chatham falls in January, around 27°F on average.
When can I start a vegetable garden in Chatham?
Around mid-April, start frost-hardy crops in Chatham; tomatoes and basil belong a fortnight later.
How many rainy days does Chatham get?
Chatham records around 165 days of measurable precipitation annually.
What hardiness zone is Chatham?
Since January in Chatham averages 27°F, Chatham's USDA zone follows that floor — confirm it by ZIP.
What is the 10-day forecast for Chatham?
Chatham'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 Chatham?
See this week's day-by-day rain chances for Chatham in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Chatham?
Current conditions for Chatham and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Chatham forecast updated?
The Chatham forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Chatham?
Today's sunrise and sunset times for Chatham 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 Chatham?
The next few days in Chatham's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

The humid subtropical climate of Chatham, Illinois carries typical Januarys near 27°F and Julys around 78°F — 51°F of seasonal travel.

Across the year, Chatham collects about 38 inches of precipitation over roughly 165 days with measurable rain or snow.

From 39.7°N, Chatham sees a 51°F seasonal swing that governs Chatham's planting and frost windows.

All cities in Illinois →

Springfield, IL weather →

ZIP codes in Chatham

  • 62629

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.