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Altamont, IL 62411 Weather
Current conditions
Observed at Effingham, Effingham County Memorial Airport · 54 min ago
Forecast
10-day-
Wednesday Night
Mostly clear, with a low around 45. North wind around 1 mph.
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Thursday
Sunny, with a high near 75. Northeast wind around 2 mph.
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Thursday Night
Clear, with a low around 46. East wind around 2 mph.
National Weather Service forecast updated 1 day ago.
Hourly
Hourly forecast- Now50°
- 2 AM48°
- 3 AM47°
- 4 AM47°
- 5 AM46°
- 6 AM46°
- 7 AM45°
- 8 AM47°
- 9 AM53°
- 10 AM61°
- 11 AM66°
- 12 PM70°
- 1 PM72°
- 2 PM74°
- 3 PM75°
- 4 PM74°
- 5 PM71°
- 6 PM68°
- 7 PM64°
- 8 PM61°
- 9 PM57°
- 10 PM54°
- 11 PM52°
- Fri12 AM51°
10-day forecast
Details- TonightOct 20Clear43°
- WedOct 21Sunny45°73°
- TodayOct 22Sunny46°75°
- FriOct 23Sunny45°73°
- SatOct 24Mostly Sunny48°74°
- SunOct 25Mostly Sunny49°77°
- MonOct 26Partly Sunny47°73°
- TueOct 27Mostly Sunny66°
- WedOct 28Cloudy41°57°
- ThuOct 29Sunny36°56°
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 in Illinois
More weather news-
Another beautiful day ahead for Central IllinoisDECATUR, Ill. (WAND) – If you’re looking for a reason to get outside, Tuesday is your day. A high-pressure system settling over the Midwest is bringing abundant sunshine and calm winds to Central Illinois, with…
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The winter weather outlook for central and southeast Illinois has been released, and a detailed summary is available at this link. Some of the highlights: Current Conditions Latest Observations Daily Climate Maps…
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One of the year’s most pleasant weather stretches arrives in Central IllinoisDECATUR, Ill. (WAND) – A beautiful stretch of sunshine and mild temperatures is settling into the region, and it’s the perfect time to get outside and enjoy it. High pressure is taking control of the Midwest, locking in…
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A great week ahead for Central IllinoisWAND DECATUR, Ill. (WAND) – A wonderful weekend across Central Illinois carries into the start of the workweek. Overnight lows dip back into the upper 30s tonight with a small risk for patchy frost, though coverage will…
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Sunshine, chilly mornings and a big warm-up ahead for central IllinoisCENTRAL ILLINOIS (25News Now) - Fall is making an appearance across central Illinois this weekend, but don’t get too comfortable with the chilly temperatures. After a cold start on Sunday morning, sunshine will help…
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Overnight Frost Advisory for parts of Illinois, NW IndianaCBS News Colorado 10pm Saturday CBS News Detroit Weekend 11pm CBS News Los Angeles Weekend 9pm CBS News Philadelphia Weekend 11pm KDKA News Weekend 11pm CBS News Texas Weekend 10pm
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Frost advisory back in effect for Central IllinoisWAND DECATUR, Ill. (WAND) – Another cool day starts the weekend across Central Illinois with highs Saturday only reaching the upper 50s under plenty of sunny skies. Strong high pressure remains in control keeping skies…
- Illinois Winter Weather: First Snow Before Thanksgiving, Nov. 26?
Chicago, IL – Illinois residents wondering when the first measurable snowfall of the 2026 winter season might arrive could see dramatically different conditions depending on where they live. While Chicago typically…
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Frosty Nights Ahead Before a Warm-Up Arrives in Central IllinoisCENTRAL ILLINOIS (25News Now) - Central Illinois is in for a chilly weekend, with temperatures dropping into the 30s and frost possible overnight. But after a cool start to the weekend, a warming trend will bring…
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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…
Sun & moon
Nearby
Forecasters' discussion
From the National Weather Service office in ILX, issued 12 hrs ago
Key Messages
- Sunny mild days and cool nights persist across central and southeast Illinois through Sunday, with highs in the mid- upper 70s and lows in the 40s.
- A cold front moves across the region early next week, bringing prospects for light rain, followed by cooler temperatures.
Discussion
Issued at 1211 PM CDT Wed Oct 21 2026
Surface ridge axis centered across the area provides quiet, clear conditions across central and southeast Illinois. Dry air and subsidence will continue to produce mainly clear skies and large diurnal temperature swings over the next several days.
Mid-level heights build across the Mississippi Valley Friday and this weekend as the surface high slips farther east. Models show strong consensus on establishing persistent southerly return flow. 850-hPa temperatures in the lower teens C, along with deeper mixing support afternoon highs around 80F on Sunday, around 15 degrees above climatological averages.
Medium-range deterministic solutions (ECMWF, ECMWF-AI, and GFS) and the ensemble suite diverge early next week regarding the progression of an upstream longwave trough and associated surface cold front. The deterministic GFS exhibits a faster frontal transit across central Illinois Monday evening with stronger pre-frontal 850-hPa flow (4050 kt). Conversely, the ECMWF and ECMWF-AI are roughly 6 to 12 hours slower, maintaining a broader frontal structure and tracking the primary boundary through the forecast area Tuesday. GEFS and ECMWF ensemble members favor this slower progression. Latest NBM run has lowered PoPs below mentionable levels, but this will likely change as the system develops. Behind the front, a shot of cooler air will move in, returning temperatures to more seasonable levels Tue-Wed.
Aviation
Issued at 1211 PM CDT Wed Oct 21 2026
Another cycle of VFR conditions and light/variable winds with high pressure in control.
Ilx Watches
None.
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.