Fairfield, Illinois Weather
Fireflies pulse through the magnolias. Day 77 of spring. Read this microseason across nine climate regions →
Fairfield weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——84°60°—
- FridayJun 5Overcast——87°65°+3°
- SaturdayJun 6Drizzle11%—84°64°-3°
- SundayJun 7Showers29%0.17″79°70°-5°
- MondayJun 8Showers58%0.13″79°69°0°
- TuesdayJun 9Light Drizzle36%—85°69°+6°
- WednesdayJun 10Thunderstorm25%—85°71°0°
Ozone at AQI 33 now. AQI down 36 over the last 6 hours — air quality is improving sharply. With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 15 by mid-afternoon.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 8 AM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 33 now. With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 15 by mid-afternoon.
- Present
- AQI 33
- UV peak
- 3.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 15
PM × Wind × Precip
PM2.5 at 5.7 µg/m³ (AQI 32) with a 0.93 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.93
- 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
- 4:17 AM
- Moonset
- 2:00 PM
- In sign
- ♑︎ Capricorn
Fireflies pulse through the magnolias
Fairfield at a glance
- Today vs. normal: 15°F below the seasonal normal for this latitude
- Last frost: April 6 (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 — Fairfield
SPC has placed Fairfield 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.