Potomac, Illinois Weather
Cicadas claim the scorching afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Potomac weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Light Showers57%0.11″89°71°—
- SundayJul 5Overcast56%—80°69°-9°
- MondayJul 6Light Drizzle10%—82°65°+2°
- TuesdayJul 7Mostly Clear——81°61°-1°
- WednesdayJul 8Clear12%—82°62°+1°
- ThursdayJul 9Showers37%0.25″83°69°+1°
- FridayJul 10Light Drizzle32%0.01″77°70°-6°
AQI 31 (Good), driven by PM2.5. AQI down 10 over the last 6 hours (gradual decline). PM2.5 at 4.7 µg/m³ (AQI 26) with a 0.90 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 4.7 µg/m³ (AQI 26) with a 0.90 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.90
- 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).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 10:46 PM
- Moonset
- 9:57 AM
- In sign
- ♓︎ Pisces
Cicadas claim the scorching afternoon
Potomac at a glance
- Today vs. normal: 3°F above the seasonal normal for this latitude
- Last frost: April 18 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 61865
16-Day Forecast — Potomac
- Sat89°71°57%
- Sun80°69°56%
- Mon82°65°10%
- Tue81°61°6%
- Wed82°62°12%
- Thu83°69°37%
- Fri77°70°32%
- Sat83°66°24%
- Sun70°58°9%
- Mon71°57°8%
- Tue77°59°11%
- Wed80°63°20%
- Thu82°65°25%
- Fri79°69°29%
- Sat85°70°26%
- Sun81°72°35%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 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 — Potomac
SPC has placed Potomac in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
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.
ZIP codes in Potomac
- 61865