Harman US

Byron, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Byron, a city in Ogle County, Illinois.

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 for Byron

WhenTempForecastWindPrecip
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) 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

Nearby towns & communities

All Illinois locations ›

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 Nov 3, 2026.