Eureka, IL Weather & Growing Conditions
This Afternoon
81°F
Mostly Cloudy
Mostly cloudy, with a high near 81. South wind around 8 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 81°F | Mostly Cloudy | 8 mph S | 11% |
| Tonight | 68°F | Mostly Cloudy then Chance Showers And Thunderstorms | 7 mph SSW | 34% |
| Sunday | 75°F | Chance Showers And Thunderstorms | 6 to 14 mph NNE | 50% |
| Sunday Night | 57°F | Chance Showers And Thunderstorms | 12 to 15 mph NE | 45% |
| Monday | 65°F | Rain Showers Likely | 15 mph ENE | 67% |
| Monday Night | 53°F | Chance Rain Showers | 12 to 15 mph ENE | 54% |
| Tuesday | 64°F | Chance Rain Showers | 14 mph NE | 54% |
| Tuesday Night | 51°F | Slight Chance Rain Showers then Mostly Cloudy | 7 to 14 mph NE | 15% |
| Wednesday | 66°F | Partly Sunny | 8 to 12 mph NNE | 3% |
| Wednesday Night | 52°F | Partly Cloudy | 3 to 10 mph NNE | 2% |
| Thursday | 70°F | Partly Sunny | 7 mph NNE | 2% |
| Thursday Night | 55°F | Mostly Cloudy | 2 to 6 mph NE | 10% |
| Friday | 73°F | Partly Sunny | 3 to 7 mph NE | 7% |
| Friday Night | 54°F | Partly Cloudy | 6 mph NE | 7% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Eureka, IL
Last spring frost
Apr 21
First fall frost
Oct 17
Growing season
178 days
Hardiness zone
5b
Explore more for Eureka, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Congerville 2Nw, Il (6.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.