Smithboro, IL Weather & Growing Conditions
This Afternoon
99°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Sunny. High near 99, with temperatures falling to around 95 in the afternoon. Heat index values as high as 102. Southeast wind around 5 mph. Chance of precipitation is 30%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 99°F | Chance Showers And Thunderstorms | 5 mph SE | 26% |
| Tonight | 71°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 5 mph E | 24% |
| Saturday | 96°F | Mostly Sunny | 2 to 6 mph SW | 7% |
| Saturday Night | 72°F | Mostly Cloudy | 3 mph S | 3% |
| Sunday | 93°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 1 to 6 mph W | 19% |
| Sunday Night | 65°F | Chance Showers And Thunderstorms | 7 mph N | 46% |
| Monday | 80°F | Showers And Thunderstorms Likely | 6 to 10 mph NE | 59% |
| Monday Night | 58°F | Showers And Thunderstorms Likely | 6 to 12 mph NE | 59% |
| Tuesday | 73°F | Slight Chance Rain Showers then Partly Sunny | 12 mph N | 24% |
| Tuesday Night | 54°F | Mostly Cloudy | 5 to 12 mph N | 5% |
| Wednesday | 75°F | Mostly Sunny | 6 to 9 mph N | 3% |
| Wednesday Night | 54°F | Partly Cloudy | 2 to 8 mph N | 3% |
| Thursday | 75°F | Mostly Sunny | 2 to 8 mph N | 2% |
| Thursday Night | 56°F | Partly Cloudy | 2 to 7 mph NE | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Smithboro, IL
Last spring frost
Apr 10
First fall frost
Oct 24
Growing season
196 days
Hardiness zone
6b
Explore more for Smithboro, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Vandalia, Il (13.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.