Glen Carbon, Illinois Weather
Fireflies pulse through the magnolias. Day 77 of spring. Read this microseason across nine climate regions →
Glen Carbon weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——85°60°—
- FridayJun 5Overcast11%—88°68°+3°
- SaturdayJun 6Light Rain15%0.08″87°67°-1°
- SundayJun 7Showers43%0.49″78°70°-9°
- MondayJun 8Showers63%—89°69°+11°
- TuesdayJun 9Thunderstorm38%—93°73°+4°
- WednesdayJun 10Overcast18%—96°75°+3°
Ozone at AQI 71 — peak already passed at 1 PM under partly cloudy skies. AQI up 29 in the last 6 hours — air quality is degrading. Levels should ease through evening.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 71 — peak already passed at 1 PM under partly cloudy skies. Levels should ease through evening.
- Present
- AQI 71
- UV peak
- 2.3 at earlier today
- Sky at peak
- partly cloudy
- Projected peak
- AQI 71
PM × Wind × Precip
PM2.5 at 9.3 µg/m³, PM10 at 11.5 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.81
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 4:25 AM
- Moonset
- 2:06 PM
- In sign
- ♒︎ Aquarius
Fireflies pulse through the magnolias
Glen Carbon at a glance
- Today vs. normal: 9°F above the seasonal normal for this latitude
- Last frost: April 9 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 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 — Glen Carbon
SPC has placed Glen Carbon in the General Thunderstorms category for severe thunderstorms tomorrow.
- TODAYNONENo severe risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
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.