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Waterloo, IL Weather
Current conditions
Observed at St. Louis Downtown Airport · 32 min ago
Forecast
10-day-
Tonight
Mostly clear, with a low around 46. Southeast wind around 2 mph.
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Wednesday
Sunny, with a high near 73. Northwest wind around 2 mph.
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Wednesday Night
Mostly clear, with a low around 49. East wind around 2 mph.
National Weather Service forecast updated 1 hr ago.
Hourly
Hourly forecast- Now55°
- 10 PM54°
- 11 PM53°
- Wed12 AM52°
- 1 AM51°
- 2 AM50°
- 3 AM49°
- 4 AM48°
- 5 AM48°
- 6 AM48°
- 7 AM47°
- 8 AM49°
- 9 AM55°
- 10 AM60°
- 11 AM65°
- 12 PM68°
- 1 PM70°
- 2 PM72°
- 3 PM72°
- 4 PM72°
- 5 PM71°
- 6 PM67°
- 7 PM63°
- 8 PM60°
10-day forecast
Details- TonightOct 20Mostly Clear46°
- WedOct 21Sunny49°73°
- ThuOct 22Sunny46°75°
- FriOct 23Sunny46°74°
- SatOct 24Mostly Sunny49°76°
- SunOct 25Mostly Sunny50°78°
- MonOct 26Partly Sunny48°74°
- TueOct 27Partly Sunny67°
- WedOct 28Rain0.07 in53°62°
- ThuOct 29Cloudy50°62°
Days after the National Weather Service's seven are MET Norway's outlook, a computer model with no forecaster's review.
Radar
Full mapWeather news near Waterloo
More weather news-
Tracking a cool night, pleasant TuesdayTONIGHT: Mostly clear and cool with lows in the mid-40s. TOMORROW: Mostly sunny and mild with highs in the lower 70s. EXTENDED: We'll be cool again overnight as temperatures fall to the mid-40s. We'll see gradual…
- St. Louis Weather Forecast Friday Through Thursday
St. Louis is trading late-summer warmth for a blustery fall reset Friday: mostly cloudy skies, a high near 55, and northwest winds around 17 mph with gusts up to 33 mph. A few rain showers could move through after 3…
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Dangerous Freeze Warnings Issued for Iowa, Wisconsin, Minnesota and Illinois as Temperatures DropFreeze Warnings take effect early Saturday across much of Iowa, Wisconsin, southeast and central Minnesota and northern Illinois, with lows as cold as 26 degrees expected. Seven National Weather Service offices issued…
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First Alert Weather Day Today: Low Severe Storm Chance 2 - 7PMKMOV - Outlying Areas Could See Frost Saturday AM and Sunday AM Today: Expect lots of cloud cover today with temperatures nearing 80°. Isolated Severe Storms Remain Possible this Afternoon from 2PM- 7PM: This is a…
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Damaging Winds Possible in Illinois and Missouri ThursdayParts of Missouri and most of Illinois are likely to experience the type of thunderstorm you'd expect to see during the Spring months. Forecasters are warning of a possible damaging wind event that will likely leave…
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This week's record heat caps hottest Jan.-Sept. on record in USIf it feels like summer never left, the numbers back you up. This week brought a fresh wave of record-breaking heat across the country, even as calendars flip toward Halloween. In a word: hot. According to U.S. National…
- Will colorful fall foliage peak soon in the metro-east? When to leaf peep
With October well underway, some leaves are beginning to turn in southwestern Illinois, but when will fall foliage peak? The southwestern Illinois region offers many picturesque spots to enjoy fall foliage, from hiking…
- Daily high-temperature records broken or tied on October 13 across parts of the central U.S.
Five daily high-temperature records were broken and one was tied at six sites across Kansas, Oklahoma, Missouri and Illinois on October 13, 2026. Temperatures at the sites reached 32.8–33.9°C (91–93°F), or 9.4–13.3°C…
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Tracking storms with heavy rain moving in late tonightTONIGHT: Warm with storms arriving late. Some storms may produce heavy rain and strong wind gusts. Lows in the upper 60s. TOMORROW: Rain and storms likely early, becoming more scattered by afternoon. Highs in the upper…
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Illinois to get brief taste of fall weather this weekMany different weather conditions are impacting Illinois this week. It started Monday with record heat. “Middle 90s in Metro East St. Louis,” said Meteorologist Paul Otto with Freese-Notis Weather during a Tuesday guest…
Air quality
Acceptable. Unusually sensitive people should consider limiting prolonged outdoor exertion.
Forecast
- TueModerate
- WedModerate
- ThuModerate
St. Louis (Metro-east), IL reporting area · 1 hr ago. Data from AirNow (EPA and its state, local and tribal partners); preliminary and subject to change.
Sun & moon
Almanac
MonthlyBelleville Siu Research, records since 1948. Normals 1991–2020. Data from NOAA's Regional Climate Centers (ACIS).
Nearby
- St. Louis 33 km
- Saint Charles 58 km
- Florissant 53 km
- Chesterfield 52 km
- Belleville 25 km
- Oakville 20 km
- Wildwood 52 km
- University City 38 km
- Ballwin 45 km
- Granite City 41 km
- O'Fallon 35 km
- Mehlville 24 km
Forecasters' discussion
From the National Weather Service office in LSX, issued 15 hrs ago
Key Messages
- Dry and seasonably warm conditions will persist through the end of the week.
Short Term
Issued at 227 AM CDT Tue Oct 20 2026
The forecast for the next several days can be summed up in one phrase - status quo. With an omega block in place in the mid-levels and high pressure stationed over the eastern CONUS at the surface, there is no reason for our sensible weather to change. The small increases in temperature we expect over the week can be attributed to persistent insolation rather than any sort of advection or dynamical reasoning. High clouds blowing into the region from the southern Plains may enter Mid-Missouri slightly before peak heating, which would prevent that area from gaining that degree or two of warmth this afternoon - a negligible difference on human skin. In all, the forecast today calls for highs around 70 degrees with very little wind and plenty of sun. Add a degree and we have the forecast for Wednesday as well. The high clouds and warmer afternoon will support higher low temperatures tonight for our Missouri counties. To the east where skies will be clearer for longer, radiational cooling is expected to create similar conditions to this morning.
Long Term
Issued at 227 AM CDT Tue Oct 20 2026
The forecast from Wednesday night through the end of the week is the same as that of today and tomorrow. Widespread 70s increase a degree or two each day unless warming is perturbed by high clouds. Late in the week mid-level ridging will be shoved eastward and flattened as a longwave trough strengthens over the Four Corners region. This system is forecast to drive a cold front into the Midwest late Saturday into Sunday, but latest model guidance indicates the front will pivot into a more west-east orientation before it reaches Missouri/central Illinois. This would keep accompanying rain and cold air to our north and lengthen the duration of our warm streak. Ensembles, aside from the GEFS, appear to support this solution. 850 mb temperatures Sunday into Monday are still forecast to be about 10C - the same as today - so a drastic cooldown within that period is not likely if the models are correct. Beyond that guidance diverges, and that's reliant on if the cold front does push through the CWA or not Monday into Tuesday. The NBM high temperature IQRs reflect the uncertainty quite well, with KSTL jumping from a 4 degree split on Sunday to a 12 degree split by Tuesday.
Aviation
Issued at 604 AM CDT Tue Oct 20 2026
After the morning river and valley fog dissipates, dry and VFR conditions with light winds will prevail through the remainder of the period.
Forecasts, observations and alerts in the United States come from the National Weather Service (NOAA); radar from NOAA's Multi-Radar Multi-Sensor system; satellite imagery from NASA's Global Imagery Browse Services (GIBS) and NOAA's GOES satellites; the map from the U.S. Geological Survey's National Map; air quality from AirNow (EPA and its partners); hurricane information from the National Hurricane Center; climate normals and records from NOAA's Regional Climate Centers (ACIS). Forecasts outside the United States and the UV index: MET Norway (CC BY 4.0); observations outside the U.S.: airport reports via NOAA's Aviation Weather Center. Place names: GeoNames (CC BY 4.0). Data are copied on a schedule and may lag the sources; for warnings that affect your safety, follow your local National Weather Service office and emergency officials. Weather news is drawn from the 4Conservative index and reflects what the press published. Terms of use.