Ontario, IL Weather Forecast
Local 7-day forecast
Showers And Thunderstorms Likely
Track current conditions, temperature changes, wind, and the full daily outlook for Ontario, IL in one place.
Showers and thunderstorms likely before 4pm, then a slight chance of showers and thunderstorms. Mostly cloudy, with a high near 78. East northeast wind 6 to 9 mph, with gusts as high as 16 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Local Weather Overview
This forecast page for Ontario, IL is designed for quick trip planning, giving you a clean read on daytime highs, overnight lows, and changing conditions across the upcoming forecast window. Latest sync: Sep 15, 2026 2:30 PM CDT.
The active forecast window currently covers Sep 16 to Sep 21, 2026 for Ontario, IL.
Page Snapshot
- Page focus
- city weather
- Forecast window
- Sep 16 to Sep 21, 2026
- Latest sync
- Sep 15, 2026 2:30 PM CDT
- Forecast office
- ILX
- Source
- NOAA / NWS
Daily Outlook
This Week in Ontario
Thursday looks like the warmest upcoming period in Ontario at 82 degrees F.
Monday Night is the coolest period ahead with temperatures near 53 degrees F.
The strongest winds are forecast for Saturday at about 12 to 16 mph SW.
Precipitation is mentioned in 11 upcoming forecast periods.
Forecast Details
- Last updated
- Sep 15, 2026 2:30 PM CDT
- Coverage
- 6 days
- Time zone
- America/Chicago
- Forecast office
- ILX
- Radar station
- KDVN
Weather data is provided by the National Weather Service and refreshed automatically for U.S. locations.
Open NOAA sourceExtended Forecast
A slight chance of showers and thunderstorms between 7pm and 1am, then showers and thunderstorms likely. Mostly cloudy, with a low around 67. East wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
Showers and thunderstorms likely before 1pm. Partly sunny, with a high near 82. West northwest wind around 6 mph. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
A chance of showers and thunderstorms after 1am. Mostly cloudy, with a low around 65. Northeast wind 3 to 7 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
A chance of showers and thunderstorms. Partly sunny, with a high near 82. East southeast wind around 10 mph, with gusts as high as 16 mph. Chance of precipitation is 50%. New rainfall amounts between a tenth and quarter of an inch possible.
A slight chance of showers and thunderstorms before 7pm, then a chance of showers and thunderstorms. Partly cloudy, with a low around 67. Chance of precipitation is 30%.
A chance of rain showers before 1pm, then a chance of showers and thunderstorms. Mostly sunny, with a high near 82. Chance of precipitation is 40%.
Showers and thunderstorms likely. Mostly cloudy, with a low around 63.
A chance of rain showers before 1pm, then a chance of showers and thunderstorms. Partly sunny, with a high near 73.
A chance of showers and thunderstorms. Mostly cloudy, with a low around 56.
A slight chance of rain showers before 7am. Mostly sunny, with a high near 71.
Partly cloudy, with a low around 53.
Detailed Forecast
| Period | Conditions | Temp | Wind |
|---|---|---|---|
|
Wednesday
Sep 16
|
Showers And Thunderstorms Likely
|
78°F |
6 to 9 mph
ENE
|
|
Wednesday Night
Sep 16
|
Slight Chance Showers And Thunderstorms
|
67°F |
5 mph
E
|
|
Thursday
Sep 17
|
Showers And Thunderstorms Likely
|
82°F |
6 mph
WNW
|
|
Thursday Night
Sep 17
|
Mostly Cloudy then Chance Showers And Thunderstorms
|
65°F |
3 to 7 mph
NE
|
|
Friday
Sep 18
|
Chance Showers And Thunderstorms
|
82°F |
10 mph
ESE
|
|
Friday Night
Sep 18
|
Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms
|
67°F |
8 to 14 mph
SE
|
|
Saturday
Sep 19
|
Chance Rain Showers
|
82°F |
12 to 16 mph
SW
|
|
Saturday Night
Sep 19
|
Showers And Thunderstorms Likely
|
63°F |
9 mph
NW
|
|
Sunday
Sep 20
|
Chance Rain Showers
|
73°F |
8 to 12 mph
N
|
|
Sunday Night
Sep 20
|
Chance Showers And Thunderstorms
|
56°F |
7 to 10 mph
NNE
|
|
Monday
Sep 21
|
Slight Chance Rain Showers then Mostly Sunny
|
71°F |
8 to 13 mph
NE
|
|
Monday Night
Sep 21
|
Partly Cloudy
|
53°F |
6 to 10 mph
NE
|
Nearby Forecasts
Explore weather pages for nearby cities and major places around Ontario.