South Beloit, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for South Beloit, a city in Winnebago County, Illinois.
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. Southwest wind around 10 mph.
7-day forecast for South Beloit
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 10 mph SW | 9% |
| Tonight | 64°F | Chance Showers And Thunderstorms | 0 to 5 mph W | 74% |
| Wednesday | 76°F | Showers And Thunderstorms Likely | 0 to 5 mph NW | 74% |
| Wednesday Night | 58°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 0 to 5 mph NW | 61% |
| Thursday | 78°F | Chance Rain Showers then Partly Sunny | 0 to 5 mph NE | 29% |
| Thursday Night | 57°F | Mostly Clear | 0 mph | 10% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph S | 3% |
| Friday Night | 61°F | Mostly Clear | 0 to 5 mph S | 5% |
| Saturday | 83°F | Mostly Sunny | 0 to 10 mph SW | 11% |
| Saturday Night | 66°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph S | 24% |
| Sunday | 85°F | Slight Chance Showers And Thunderstorms | 5 to 15 mph SW | 24% |
| Sunday Night | 66°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 to 10 mph SW | 44% |
| Monday | 84°F | Chance Rain Showers | 5 to 10 mph S | 43% |
| Monday Night | 66°F | Chance Showers And Thunderstorms | 5 to 10 mph NW | 44% |
Forecast source: National Weather Service (api.weather.gov) for South Beloit (42.485, -89.027). Updated through the day.
Growing snapshot for South Beloit
Last spring frost
May 1
First fall frost
Oct 12
Growing season
162 days
Hardiness zone
5b
More local growing data for South Beloit: nearby ZIP 61080 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Cherry Valley
Durand
Loves Park
Machesney Park
New Milford
Pecatonica
Rockford
Rockton
Roscoe
Westlake Village
Winnebago
Climate data from the nearest NOAA station, Beloit, Wi (2.9 mi from South Beloit). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.