Harrisburg, Illinois Weather
Fireflies pulse through the magnolias. Day 76 of spring. Read this microseason across nine climate regions →
Harrisburg weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——79°53°—
- ThursdayJun 4Overcast——82°60°+3°
- FridayJun 5Overcast——81°62°-1°
- SaturdayJun 6Drizzle——84°65°+3°
- SundayJun 7Drizzle29%—88°70°+4°
- MondayJun 8Showers50%—79°70°-9°
- TuesdayJun 9Drizzle32%—75°70°-4°
Ozone at AQI 58 — peak already passed at 1 PM under clear skies. AQI up 22 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 58 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 58
- UV peak
- 0.7 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 58
PM × Wind × Precip
PM2.5 at 5.4 µg/m³ (AQI 30) with a 0.87 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.87
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 3:38 AM
- Moonset
- 1:01 PM
- In sign
- ♑︎ Capricorn
Fireflies pulse through the magnolias
Harrisburg at a glance
- Today vs. normal: 77°F — typical for the season
- Last frost: April 2 (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 3, 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.