South Beloit, IL Weather Forecast
Winnebago County, Illinois
Seven-day outlook
38–67°F across the weekThe week runs between 39° and 67°, with Tuesday the warmest day of it. There is no real trend across it: one day looks much like the next. Saturday is the wettest day, peaking near 65%.
Forecasts come from the National Weather Service's own computer models, and current conditions from the nearest reporting weather station. Both are served through the weather API. A forecast is guidance, not a warning, and anything the Weather Service has actually issued is on the live map.
The written summaries on this page are generated from the forecast data above, not by a meteorologist. Each sentence is a reading of the same numbers you can see, and no forecaster has reviewed them.
About the South Beloit forecast
South Beloit sits at 42.4848°N, 89.0274°W in Winnebago County, Illinois. The forecast above is drawn for that point from the National Weather Service's own computer models: a seven-day outlook, and a finer-grained one covering the next eighteen hours where it reaches, and the radar and alert panels show what the Weather Service has out over the area right now.
- County
- Winnebago County
- Coordinates
- 42.4848°N, 89.0274°W
- Population
- 7,893 · 2023 estimate
- Land area
- 6.144 sq mi
Place data from the US Census Bureau. Coordinates are the Census internal point for South Beloit, and the forecast is for that location, not for every address inside the city limits, and a large city can have real weather differences from one side to the other.
How well can the network see South Beloit?
The nearest Doppler radar is KMKX (Milwaukee, WI), 41 miles to the NE. A WSR-88D's lowest routine scan sits half a degree above horizontal, and the earth curves away beneath it, so by the time that beam reaches South Beloit its center is about 2,700 ft above ground. That is comfortably inside the useful range. The lowest scan passes low enough over South Beloit to show rotation in the part of a storm where tornadoes actually form. South Beloit is closer to its radar than 54% of US cities.
The closest instrument actually measuring the air is KJVL · Janesville/S Wisconsin Rgnl on the ASOS/AWOS network, 9.5 miles away. Near enough to be representative on most days, though a summer thunderstorm can soak one and miss the other entirely.
Beam height is the standard 4/3-earth approximation for the 0.5° scan and assumes normal refraction; it is where the center of the beam is, not its edges, and unusual temperature profiles bend it. Radar siting from the NWS WSR-88D network, station positions from the Illinois observing network as of this build.
Forecasts near South Beloit
- Beloit, WI3 mi
- Rockton, IL3 mi
- Roscoe, IL4 mi
- Machesney Park, IL8 mi
- Rock, WI10 mi
- Loves Park, IL10 mi
- Poplar Grove, IL13 mi
- Janesville, WI14 mi
Elsewhere in Illinois
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