Somonauk, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Somonauk, a village in Dekalb County, Illinois.
Overnight
62°F
Mostly Clear
Mostly clear, with a low around 62. South wind around 5 mph.
7-day forecast for Somonauk
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 62°F | Mostly Clear | 5 mph S | 0% |
| Tuesday | 85°F | Mostly Sunny | 5 to 10 mph SSW | 1% |
| Tuesday Night | 67°F | Mostly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph SSW | 30% |
| Wednesday | 80°F | Showers And Thunderstorms Likely | 5 mph WSW | 71% |
| Wednesday Night | 64°F | Showers And Thunderstorms | 5 mph NNW | 87% |
| Thursday | 80°F | Rain Showers Likely then Slight Chance Showers And Thunderstorms | 5 mph E | 59% |
| Thursday Night | 62°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph SSE | 22% |
| Friday | 82°F | Mostly Sunny | 0 to 5 mph SE | 6% |
| Friday Night | 64°F | Mostly Clear | 0 to 5 mph S | 9% |
| Saturday | 84°F | Mostly Sunny | 5 to 10 mph SSW | 11% |
| Saturday Night | 69°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 17% |
| Sunday | 86°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph SW | 17% |
| Sunday Night | 70°F | Chance Showers And Thunderstorms | 10 mph SSW | 33% |
| Monday | 86°F | Chance Rain Showers then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 33% |
Forecast source: National Weather Service (api.weather.gov) for Somonauk (41.635, -88.687). Updated through the day.
Growing snapshot for Somonauk
Last spring frost
Apr 28
First fall frost
Oct 13
Growing season
166 days
Hardiness zone
5b
More local growing data for Somonauk: nearby ZIP 60552 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Cortland
DeKalb
Genoa
Hinckley
Kingston
Kirkland
Lake Holiday
Malta
Sandwich
Shabbona
Sycamore
Waterman
Climate data from the nearest NOAA station, Chicago Aurora Muni Ap, Il (13.6 mi from Somonauk). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.