Byron, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Byron, a city in Ogle County, Illinois.
Tonight
62°F
Slight Chance Rain Showers then Showers And Thunderstorms Likely
A slight chance of rain showers before midnight, then showers and thunderstorms likely. Some of the storms could produce heavy rain. Mostly cloudy, with a low around 62. East wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between three quarters and one inch possible.
7-day forecast for Byron
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 62°F | Slight Chance Rain Showers then Showers And Thunderstorms Likely | 10 mph E | 60% |
| Saturday | 78°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 91% |
| Saturday Night | 62°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 to 10 mph NNE | 77% |
| Sunday | 67°F | Showers And Thunderstorms | 10 to 15 mph NE | 75% |
| Sunday Night | 52°F | Rain Showers Likely | 10 to 15 mph NE | 55% |
| Monday | 65°F | Chance Rain Showers | 15 mph ENE | 43% |
| Monday Night | 47°F | Chance Rain Showers | 10 to 15 mph NE | 40% |
| Tuesday | 64°F | Chance Rain Showers | 10 to 15 mph NE | 32% |
| Tuesday Night | 46°F | Mostly Cloudy | 5 to 10 mph NE | 8% |
| Wednesday | 67°F | Partly Sunny | 5 to 10 mph NE | 4% |
| Wednesday Night | 47°F | Partly Cloudy | 0 to 10 mph NE | 2% |
| Thursday | 68°F | Mostly Sunny | 0 to 5 mph NNE | 5% |
| Thursday Night | 49°F | Partly Cloudy | 0 to 5 mph NE | 5% |
| Friday | 71°F | Mostly Sunny | 0 to 5 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov) for Byron (42.122, -89.267). Updated through the day.
Growing snapshot for Byron
Last spring frost
Apr 24
First fall frost
Oct 17
Growing season
174 days
Hardiness zone
5b
More local growing data for Byron: nearby ZIP 61010 weather · frost dates · planting calendar · Illinois frost dates
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Oregon
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Rochelle
Stillman Valley
Climate data from the nearest NOAA station, Rockford Gtr Rockford Ap, Il (10 mi from Byron). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.