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Decatur, IL Weather
Current conditions
Observed at Decatur Airport · 28 min ago
Forecast
10-day-
Wednesday
Sunny, with a high near 73. North northwest wind around 1 mph.
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Wednesday Night
Clear, with a low around 44. Wind around 0 mph.
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Thursday
Sunny, with a high near 75. Northeast wind 0 to 3 mph.
National Weather Service forecast updated 1 day ago.
Hourly
Hourly forecast- Now71°
- 3 PM72°
- 4 PM73°
- 5 PM71°
- 6 PM68°
- 7 PM64°
- 8 PM60°
- 9 PM57°
- 10 PM56°
- 11 PM54°
- Thu12 AM52°
- 1 AM51°
- 2 AM50°
- 3 AM48°
- 4 AM48°
- 5 AM46°
- 6 AM45°
- 7 AM46°
- 8 AM50°
- 9 AM55°
- 10 AM61°
- 11 AM66°
- 12 PM70°
- 1 PM72°
Daily forecast
Details- TueOct 20Sunny42°71°
- TodayOct 21Sunny44°73°
- ThuOct 22Sunny47°75°
- FriOct 23Sunny46°73°
- SatOct 24Mostly Sunny50°73°
- SunOct 25Mostly Sunny49°75°
- MonOct 26Mostly Sunny46°71°
- TueOct 27Cloudy46°59°
- WedOct 28Cloudy40°55°
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 Decatur
More weather news- Days shorter
WAND DECATUR, Ill. (WAND) – It doesn’t matter that we lose well over 2 minutes of daylight every day this time of year. What matters is the origin of the air mass. A northern shift in the storm track will result in…
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Sunshine and a warming trend through the weekBeautiful weather is here to stay. DECATUR, Ill. (WAND) – High pressure is in control today, bringing plenty of sunshine and mild temperatures in the upper 60s to low 70s thanks to southerly flow. Tonight will be mostly…
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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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Frost this morning, then a warming trend takes overWAND DECATUR, Ill. (WAND) – Patchy frost is expected this morning with a near area-wide Frost Advisory in effect through 9 a.m., except for Illinois River counties. High pressure is in control today, bringing plenty of…
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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…
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Frost advisory in effect for West Central Illinois; cool to start the weekendWAND DECATUR, Ill. (WAND) – Significantly cooler weather wraps up the work week behind the latest cold front with temperatures nearly 20 degrees below Thursday’s highs. Cloud cover remains through the day before skies…
- What makes a storm severe?
DECATUR, Ill. (WAND) – When we call a storm “severe,” we’re not just talking about a loud, rainy thunderstorm. The National Weather Service has a very specific definition. A thunderstorm is severe if it produces: If it…
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Strong to severe storms on tap Thursday eveningWAND DECATUR, Ill. (WAND) – Thursday will be a wet day across Central Illinois. Showers will arrive by late morning before a second round of storms moves in during the evening. The main window for strong to severe…
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Strong storms are possible this afternoon and evening across Central IllinoisDECATUR, Ill. (WAND) – An active weather day is shaping up for Central Illinois, with strong to severe thunderstorms expected to develop this afternoon and evening as a cold front lifts back into the region. The Storm…
Air quality
Acceptable. Unusually sensitive people should consider limiting prolonged outdoor exertion.
Forecast
- WedModerate
- ThuModerate
- FriModerate
Decatur, IL reporting area · 2 hrs ago. Data from AirNow (EPA and its state, local and tribal partners); preliminary and subject to change.
Sun & moon
Almanac
MonthlyDecatur Ap, records since 2000. Normals 1991–2020. Data from NOAA's Regional Climate Centers (ACIS).
Nearby
- Springfield 59 km
- Lincoln 49 km
- Taylorville 44 km
- Clinton 35 km
- Mount Zion 10 km
- Pana 51 km
- Monticello 39 km
- Sherman 56 km
- Shelbyville 50 km
- Sullivan 40 km
- Tuscola 58 km
- Rochester 50 km
Forecasters' discussion
From the National Weather Service office in ILX, issued 1 hr 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.