Round Lake, IL Weather & Growing Conditions
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. South southwest wind around 10 mph, with gusts as high as 20 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 10 mph SSW | 1% |
| Tonight | 67°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 to 10 mph WSW | 49% |
| Wednesday | 78°F | Showers And Thunderstorms Likely | 5 mph SW | 74% |
| Wednesday Night | 61°F | Showers And Thunderstorms | 0 to 5 mph WNW | 79% |
| Thursday | 78°F | Chance Rain Showers | 0 to 5 mph NNE | 51% |
| Thursday Night | 59°F | Partly Cloudy | 0 to 5 mph NE | 13% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph SSW | 3% |
| Friday Night | 62°F | Mostly Clear | 0 to 5 mph S | 7% |
| Saturday | 84°F | Mostly Sunny | 0 to 5 mph SW | 10% |
| Saturday Night | 68°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph SW | 21% |
| Sunday | 85°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 21% |
| Sunday Night | 67°F | Chance Showers And Thunderstorms | 5 to 10 mph WSW | 46% |
| Monday | 84°F | Chance Rain Showers | 5 mph SSW | 46% |
| Monday Night | 67°F | Chance Showers And Thunderstorms | 5 mph NW | 47% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Round Lake, IL
Last spring frost
Apr 24
First fall frost
Oct 23
Growing season
180 days
Hardiness zone
5b
Explore more for Round Lake, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Lake Villa 2Ne, Il (5.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.