Ottawa, Illinois Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Ottawa weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Heavy Rain73%3.5″83°71°—
- SundayJul 5Overcast16%—82°69°-1°
- MondayJul 6Overcast——81°64°-1°
- TuesdayJul 7Overcast——81°59°0°
- WednesdayJul 8Overcast10%—81°64°0°
- ThursdayJul 9Thunderstorm47%0.04″80°67°-1°
- FridayJul 10Overcast34%—80°63°0°
AQI 27 (Good), driven by PM2.5. AQI down 7 over the last 6 hours (gradual decline). PM2.5 at 7.2 µg/m³, PM10 at 8.1 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 10 PM.
What's driving it
Ozone × UV × Sky
Ozone at AQI 32. Overcast through the UV peak window (cloud cover ~81%) — afternoon ozone should stay flat.
- Present
- AQI 32
- UV peak
- 3.4 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 7
PM × Wind × Precip
PM2.5 at 7.2 µg/m³, PM10 at 8.1 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.89
- Wind
- calm
- Recent rain
- 1h in last 6h
- Pattern
- background
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
- 10:52 PM
- Moonset
- 10:00 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Ottawa at a glance
- Today vs. normal: 10°F above the seasonal normal for this latitude
- Last frost: April 24 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 61350
16-Day Forecast — Ottawa
- Sat83°71°73%
- Sun82°69°16%
- Mon81°64°6%
- Tue81°59°2%
- Wed81°64°10%
- Thu80°67°47%
- Fri80°63°34%
- Sat82°64°14%
- Sun69°59°9%
- Mon73°57°9%
- Tue78°60°10%
- Wed79°62°32%
- Thu83°65°25%
- Fri81°69°32%
- Sat85°70°24%
- Sun83°72°29%
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 — Ottawa
SPC has placed Ottawa in the Marginal Risk category for severe thunderstorms today.
- TODAYMRGLMarginal Risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3NONENo severe risk
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 Ottawa
- 61350