Potomac, Illinois Weather
Fireflies pulse through the magnolias. Day 76 of spring. Read this microseason across nine climate regions →
Potomac weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast——84°52°—
- ThursdayJun 4Overcast——86°58°+2°
- FridayJun 5Light Drizzle30%—81°64°-5°
- SaturdayJun 6Showers50%—81°65°0°
- SundayJun 7Overcast47%—85°67°+4°
- MondayJun 8Showers23%—79°67°-6°
- TuesdayJun 9Overcast16%—79°69°0°
Ozone at AQI 51. AQI flat over the last 6 hours (within ±3 points). Overcast through the UV peak window (cloud cover ~95%) — afternoon ozone should stay flat.
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 51. Overcast through the UV peak window (cloud cover ~95%) — afternoon ozone should stay flat.
- Present
- AQI 51
- UV peak
- 8.9 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 30
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
- 3:44 AM
- Moonset
- 12:48 PM
- In sign
- ♑︎ Capricorn
Fireflies pulse through the magnolias
Potomac at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: April 18 (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.
SPC Convective Outlook
Storm Prediction Center — Potomac
SPC has placed Potomac 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.