Round Lake, IL Weather & Growing Conditions
Overnight
61°F
Showers And Thunderstorms
Showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy. Low around 61, with temperatures rising to around 64 overnight. East southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between three quarters and one inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 61°F | Showers And Thunderstorms | 10 mph ESE | 100% |
| Saturday | 75°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SSE | 100% |
| Saturday Night | 60°F | Showers And Thunderstorms | 5 to 10 mph ENE | 94% |
| Sunday | 68°F | Chance Showers And Thunderstorms | 10 to 20 mph NNE | 52% |
| Sunday Night | 54°F | Mostly Cloudy | 15 mph NE | 13% |
| Monday | 63°F | Slight Chance Rain Showers | 15 mph ENE | 23% |
| Monday Night | 50°F | Mostly Cloudy | 10 to 15 mph ENE | 14% |
| Tuesday | 62°F | Mostly Cloudy | 10 to 15 mph NE | 12% |
| Tuesday Night | 50°F | Mostly Cloudy | 5 to 15 mph NE | 6% |
| Wednesday | 64°F | Partly Sunny | 5 to 10 mph NE | 11% |
| Wednesday Night | 51°F | Mostly Cloudy | 0 to 10 mph NNE | 4% |
| Thursday | 66°F | Partly Sunny | 5 mph NNE | 5% |
| Thursday Night | 51°F | Mostly Cloudy | 0 to 5 mph NNE | 4% |
| Friday | 69°F | Mostly Sunny | 0 to 5 mph NE | 5% |
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 Sep 19, 2026.