Simpson, Illinois Weather
Fireflies pulse through the magnolias. Day 76 of spring. Read this microseason across nine climate regions →
Simpson weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——81°54°—
- ThursdayJun 4Overcast——83°61°+2°
- FridayJun 5Overcast——82°60°-1°
- SaturdayJun 6Heavy Drizzle——83°65°+1°
- SundayJun 7Heavy Drizzle39%—87°69°+4°
- MondayJun 8Showers55%—79°70°-8°
- TuesdayJun 9Drizzle38%0.01″75°69°-4°
Ozone at AQI 61 now. AQI up 8 over the last 6 hours (gradual rise). With UV 9.2 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 75 by mid-afternoon.
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 61 now. With UV 9.2 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 75 by mid-afternoon.
- Present
- AQI 61
- UV peak
- 9.2 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 75
PM × Wind × Precip
PM2.5 at 5.9 µg/m³ (AQI 33) 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).










































The higher the clouds, the finer the weather.
- Moonrise
- 3:38 AM
- Moonset
- 1:03 PM
- In sign
- ♑︎ Capricorn
Fireflies pulse through the magnolias
Simpson at a glance
- Today vs. normal: 79°F — typical for the season
- Last frost: April 1 (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.