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Round Lake Heights, Illinois Weather

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

Round Lake Heights weather forecast — hour by hour, 7-day outlook, NOAA radar

Round Lake Heights, IL
Saturday, July 4 at 11:00 AM
77
°
Overcast
Feels like
84°
Humidity
83%
Wind
5 mph
Sunrise
12:21 AM
Sunset
3:32 PM
Round Lake Heights, IL
Hour by hour · 24h
24-Hour ForecastRound Lake Heights, IL: 24-hour forecast. Temperatures range from 63 to 81 degrees Fahrenheit with a 23% chance of precipitation at 3 PM.
L 63°H 81°
Round Lake Heights, IL
7-day forecast
  1. Today
    Jul 4
    Light Drizzle
    66%
    0.04″
    81°67°—
  2. Sunday
    Jul 5
    Overcast
    18%
    —
    79°63°-2°
  3. Monday
    Jul 6
    Overcast
    —
    —
    76°60°-3°
  4. Tuesday
    Jul 7
    Overcast
    —
    —
    80°58°+4°
  5. Wednesday
    Jul 8
    Overcast
    15%
    —
    81°60°+1°
  6. Thursday
    Jul 9
    Light Drizzle
    49%
    0.04″
    77°63°-4°
  7. Friday
    Jul 10
    Overcast
    43%
    —
    77°61°0°
Round Lake Heights, IL
Next 24 hours · Mild now
58°72°86°6a12p6p12anow 77°high 81°low 63°PRECIP %
Round Lake Heights, IL
Anemometer · 24h winds · from true
NESW
From · True
NNW
335° · veering 101°
Direction
NNW
335°
Sustained
5
mph
Gust
9
mph
Peak 24h
25
avg 6
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 6 · pk 25 @ 9:00p
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 208SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 101° from the nnw.
Round Lake Heights, IL
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
986.5
-0.5 mb in 3h · steady · 29.13 inHg
Now
986.5
mb
3h
-0.5
mb
12h
-0.8
mb
24h
-3.2
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 987–990
9809859909951000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR10201025FAIR|DRY1030-21h-18h-15h-12h-9h-6h-3h-24hNOW989.7986.5986.5
−24h−18h−12h−6hnow
Deep low — expect rough seas, strong wind, and persistent rain.
Round Lake Heights, IL
Air quality
39
AQI
Good
→0 in 6h▲Peak ~46 @ 10 PM

AQI 39 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 8.5 µg/m³ (AQI 47) with a 0.91 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.

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 2.5DRIVERGood
8.5μg/m³
PM 10Good
9μg/m³
NO₂Good
10μg/m³
OzoneModerate
83μg/m³
UV IndexModerate
3.5

What's driving it

Ozone × UV × Sky

Ozone at AQI 39 now. With UV 4.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 15 around 1 PM.

Present
AQI 39
UV peak
4.0 at 1 PM
Sky at peak
partly cloudy
Projected peak
AQI 15

PM × Wind × Precip

PM2.5 at 8.5 µg/m³ (AQI 47) with a 0.91 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.

PM2.5/PM10
0.91
Wind
light
Recent rain
0h in last 6h
Pattern
stagnant smoke

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/m³330
Round Lake Heights, IL
Sky cover · visibility · 24h
Cloud cover
100%
OVERCAST
100%0%−24h−18h−12h−6hnow
Visibility
35.1mi
UNLIMITED
48 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
16:00 UTC · Round Lake Heights, 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
16:00 UTC · Round Lake Heights, IL · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Round Lake Heights, IL
Satellite · infrared · animated
Round Lake Heights, IL
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Round Lake Heights, IL
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
4:47 AM
Sunrise
12:21 AM
Daylight
15h 11m
Sunset
3:32 PM
Civil dusk
9:08 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Round Lake Heights, IL
The moon
Waning Gibbous
80% illuminated
Moonrise
10:51 PM
Moonset
9:56 AM
In sign
♓︎ Pisces
Round Lake Heights, IL
Microseason
Jul 1–5

Cicadas claim the afternoon

plant
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Round Lake Heights at a glance

  • Today vs. normal: 8°F above the seasonal normal for this latitude
  • Last frost: April 30 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

16-Day Forecast — Round Lake Heights

  1. Sat81°67°66%
  2. Sun79°63°18%
  3. Mon76°60°1%
  4. Tue80°58°1%
  5. Wed81°60°15%
  6. Thu77°63°49%
  7. Fri77°61°43%
  8. Sat82°60°10%
  9. Sun66°59°8%
  10. Mon74°55°8%
  11. Tue76°60°8%
  12. Wed80°64°26%
  13. Thu83°66°16%
  14. Fri84°68°16%
  15. Sat86°69°20%
  16. Sun86°69°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 — Round Lake Heights

SPC includes Round Lake Heights in the general thunderstorm area today — no severe risk, but storms are possible.

  • TODAYTSTMGeneral Thunderstorms
  • TOMORROWTSTMGeneral Thunderstorms
  • DAY 3NONENo severe risk

Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.

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——
April——
Maylettuce, peas, spinach, radisheslettuce, peas, radishes
Junelettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
Augusttomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
October—winter squash, tomatoes (last)
November——
December——

A year in weather

The year in Round Lake Heights tops out in July (~75°F) and dips lowest in January (~22°F), with May wettest at 3.7 inches and January driest at 1.8 inches.

MonthMean tempPrecipRainy days
January22°1.8″15
February24°1.9″13
March35°2.7″15
April47°3.4″17
May57°3.7″18
June68°3.4″15
July75°2.5″13
August74°2.8″13
September67°3.1″14
October54°2.9″13
November39°3.2″14
December26°2.3″13

Regional context

Drawing on NOAA NCEI 1991-2020 normals, Round Lake Heights's January averages 22°F and July 75°F — 53°F apart — while precipitation totals roughly 33.6 inches over some 173 days.

Round Lake Heights's precipitation spreads evenly: May peaks at 3.7 inches on 18.0 wet days, while January holds 1.8 inches over 14.6 — no month dominates Round Lake Heights's rain calendar. That lines Round Lake Heights up with places like Round Lake Beach, IL, Long Lake, IL and Fox Lake Hills, IL, fed by overlapping storm tracks.

By late-May the frosts ease in Round Lake Heights, opening the season for kale, peas, spinach, and parsnips. Hold Round Lake Heights's tender crops — tomatoes, peppers, basil — until 10-14 days past Round Lake Heights's last frost. Round Lake Heights's window closes around early-October as overnight lows return below freezing. In Round Lake Heights, low spots run 4-7°F colder than nearby slopes, nudging Round Lake Heights's frost dates a week.

Similar climates: Round Lake Beach, IL, Long Lake, IL, Fox Lake Hills, IL, Lake Villa, IL, Round Lake, IL.

Frequently asked

When does it freeze in Round Lake Heights?
In Round Lake Heights, expect the last spring frost near mid-May; Round Lake Heights's first autumn frost comes around mid-October.
What is the rainy season in Round Lake Heights?
Rainfall in Round Lake Heights peaks in May near 3.7 inches, out of about 34 inches annually.
What is the warmest month in Round Lake Heights?
July is Round Lake Heights's warmest month, averaging about 75°F.
What is the coldest month in Round Lake Heights?
Round Lake Heights bottoms out in January, with a mean near 22°F.
When can I start a vegetable garden in Round Lake Heights?
Time tomatoes in Round Lake Heights for two weeks after mid-May; peas and greens start at Round Lake Heights's frost line.
How many rainy days does Round Lake Heights get?
Expect roughly 173 wet days a year in Round Lake Heights.
What hardiness zone is Round Lake Heights?
Round Lake Heights sits in the USDA zone set by January lows near 22°F; the USDA ZIP tool gives the band.
What is the 10-day forecast for Round Lake Heights?
Round Lake Heights'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 Round Lake Heights?
See this week's day-by-day rain chances for Round Lake Heights in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Round Lake Heights?
Current conditions for Round Lake Heights and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Round Lake Heights forecast updated?
The Round Lake Heights forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Round Lake Heights?
Today's sunrise and sunset times for Round Lake Heights 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 Round Lake Heights?
The next few days in Round Lake Heights's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

Round Lake Heights, Illinois has a warm-summer humid continental climate: January averages roughly 22°F, July about 75°F, 53°F between them.

Across the year, Round Lake Heights collects about 34 inches of precipitation over roughly 173 days with measurable rain or snow.

Latitude 42.4°N gives Round Lake Heights its 53°F swing, and with it the rhythm of Round Lake Heights's growing season.

All cities in Illinois →

Round Lake Beach, IL weather →

ZIP codes in Round Lake Heights

  • 60073

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.