Lake Summerset, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lake Summerset, a community in Stephenson County, Illinois.
Today
83°F
Mostly Sunny then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5pm. Mostly sunny, with a high near 83. South southwest wind 5 to 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
7-day forecast for Lake Summerset
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 83°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 17% |
| Tonight | 64°F | Chance Showers And Thunderstorms | 5 to 10 mph WNW | 74% |
| Wednesday | 75°F | Showers And Thunderstorms Likely | 5 mph WNW | 74% |
| Wednesday Night | 58°F | Showers And Thunderstorms Likely | 0 to 5 mph NW | 58% |
| Thursday | 78°F | Chance Rain Showers then Mostly Sunny | 0 to 5 mph NE | 26% |
| Thursday Night | 58°F | Mostly Clear | 0 mph | 6% |
| Friday | 80°F | Mostly Sunny | 0 to 5 mph SSE | 5% |
| Friday Night | 62°F | Mostly Clear | 5 mph SSW | 5% |
| Saturday | 82°F | Mostly Sunny | 5 to 10 mph SSW | 11% |
| Saturday Night | 68°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 23% |
| Sunday | 84°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph SW | 23% |
| Sunday Night | 66°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 to 10 mph SW | 43% |
| Monday | 83°F | Chance Showers And Thunderstorms | 5 to 10 mph SSW | 42% |
| Monday Night | 67°F | Chance Showers And Thunderstorms | 10 mph NW | 42% |
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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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 Aug 4, 2026.