Lake Summerset, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lake Summerset, a community in Stephenson County, Illinois.
This Afternoon
70°F
Chance Rain Showers
A chance of rain showers. Mostly cloudy, with a high near 70. East southeast wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Lake Summerset
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 70°F | Chance Rain Showers | 15 mph ESE | 26% |
| Tonight | 62°F | Showers And Thunderstorms Likely | 10 to 15 mph E | 84% |
| Saturday | 75°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 10 to 15 mph ESE | 95% |
| Saturday Night | 61°F | Showers And Thunderstorms Likely | 10 mph NE | 72% |
| Sunday | 66°F | Showers And Thunderstorms Likely | 15 mph NE | 60% |
| Sunday Night | 54°F | Chance Rain Showers | 15 mph NE | 41% |
| Monday | 62°F | Chance Rain Showers | 15 mph ENE | 41% |
| Monday Night | 49°F | Chance Rain Showers | 10 to 15 mph NE | 41% |
| Tuesday | 61°F | Chance Rain Showers then Partly Sunny | 15 mph NE | 31% |
| Tuesday Night | 47°F | Mostly Cloudy | 5 to 15 mph NE | 9% |
| Wednesday | 64°F | Mostly Sunny | 5 to 10 mph NE | 5% |
| Wednesday Night | 49°F | Partly Cloudy | 5 to 10 mph NE | 2% |
| Thursday | 67°F | Mostly Sunny | 5 mph NNE | 6% |
| Thursday Night | 50°F | Partly Cloudy | 0 to 5 mph NE | 5% |
Forecast source: National Weather Service (api.weather.gov) for Lake Summerset (42.454, -89.390). Updated through the day.
Growing snapshot for Lake Summerset
Last spring frost
Apr 29
First fall frost
Oct 12
Growing season
165 days
Hardiness zone
5a
More local growing data for Lake Summerset: nearby ZIP 61019 weather · frost dates · planting calendar · Illinois frost dates
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Adeline
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Willow Lake
Winslow
Climate data from the nearest NOAA station, Brodhead Wwtp, Wi (12.4 mi from Lake Summerset). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.