Sycamore, IL Weather & Growing Conditions
Overnight
57°F
Rain Showers
Rain showers. Cloudy. Low around 57, with temperatures rising to around 60 overnight. South wind around 15 mph, with gusts as high as 30 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 57°F | Rain Showers | 15 mph S | 84% |
| Wednesday | 61°F | Slight Chance Rain Showers then Mostly Cloudy | 15 mph SSW | 21% |
| Wednesday Night | 46°F | Cloudy then Slight Chance Rain Showers | 15 mph SW | 16% |
| Thursday | 55°F | Chance Rain Showers | 10 to 15 mph WSW | 47% |
| Thursday Night | 40°F | Chance Rain Showers then Mostly Cloudy | 10 mph NW | 40% |
| Friday | 49°F | Partly Sunny | 10 to 15 mph N | 9% |
| Friday Night | 31°F | Partly Cloudy | 5 to 10 mph NNW | 0% |
| Saturday | 51°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 32°F | Mostly Clear | 0 to 5 mph W | 1% |
| Sunday | 55°F | Sunny | 5 to 10 mph W | 6% |
| Sunday Night | 34°F | Mostly Clear | 0 to 5 mph W | 0% |
| Monday | 60°F | Sunny | 0 to 10 mph WSW | 0% |
| Monday Night | 39°F | Mostly Clear | 5 mph W | 1% |
| Tuesday | 61°F | Sunny | 5 mph WNW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Sycamore, IL
Last spring frost
Apr 24
First fall frost
Oct 18
Growing season
177 days
Hardiness zone
5b
Explore more for Sycamore, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, De Kalb, Il (7.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.