Byron, IL Weather & Growing Conditions
This Afternoon
68°F
Rain
Rain and a slight chance of thunderstorms. Cloudy. High near 68, with temperatures falling to around 66 in the afternoon. South wind 15 to 20 mph, with gusts as high as 35 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 68°F | Rain | 15 to 20 mph S | 83% |
| Tonight | 56°F | Rain | 15 mph S | 87% |
| Wednesday | 59°F | Chance Rain | 15 mph SSW | 42% |
| Wednesday Night | 45°F | Chance Rain | 15 mph SW | 26% |
| Thursday | 55°F | Chance Rain | 10 to 15 mph WSW | 46% |
| Thursday Night | 39°F | Chance Rain | 5 to 10 mph NW | 33% |
| Friday | 51°F | Slight Chance Rain then Partly Sunny | 10 mph N | 16% |
| Friday Night | 30°F | Partly Cloudy | 0 to 5 mph NNW | 2% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph WNW | 2% |
| Saturday Night | 31°F | Partly Cloudy | 0 to 5 mph WSW | 4% |
| Sunday | 58°F | Mostly Sunny | 5 to 10 mph W | 14% |
| Sunday Night | 32°F | Mostly Clear | 0 to 5 mph W | 4% |
| Monday | 61°F | Sunny | 5 to 15 mph SW | 1% |
| Monday Night | 36°F | Mostly Clear | 5 to 10 mph W | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Byron, IL
Last spring frost
Apr 24
First fall frost
Oct 17
Growing season
174 days
Hardiness zone
5b
Explore more for Byron, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Rockford Gtr Rockford Ap, Il (10 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.