Vandalia, Illinois Weather
Fireflies pulse through the magnolias. Day 77 of spring. Read this microseason across nine climate regions →
Vandalia weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——82°54°—
- ThursdayJun 4Overcast——85°59°+3°
- FridayJun 5Light Drizzle10%—85°65°0°
- SaturdayJun 6Heavy Drizzle31%—87°64°+2°
- SundayJun 7Light Showers30%—85°71°-2°
- MondayJun 8Heavy Showers51%0.66″81°70°-4°
- TuesdayJun 9Thunderstorm31%—86°69°+5°
Ozone at AQI 43 now. AQI up 13 over the last 6 hours (gradual rise). With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 7 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 43 now. With UV 0.0 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 7 by mid-afternoon.
- Present
- AQI 43
- UV peak
- 0.0 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 7
PM × Wind × Precip
PM2.5 at 4.7 µg/m³ (AQI 26) with a 0.94 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.94
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 4:22 AM
- Moonset
- 2:02 PM
- In sign
- ♑︎ Capricorn
Fireflies pulse through the magnolias
Vandalia at a glance
- Today vs. normal: 8°F below the seasonal normal for this latitude
- Last frost: April 10 (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 — Vandalia
SPC has placed Vandalia in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- 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.