Lewistown, IL Weather & Growing Conditions
Tonight
70°F
Partly Cloudy then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5am. Partly cloudy, with a low around 70. East southeast wind 5 to 8 mph, with gusts as high as 17 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 70°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 8 mph ESE | 18% |
| Saturday | 89°F | Slight Chance Rain Showers then Mostly Cloudy | 3 to 8 mph S | 15% |
| Saturday Night | 68°F | Chance Showers And Thunderstorms | 6 mph NNW | 53% |
| Sunday | 79°F | Rain Showers Likely | 2 to 10 mph N | 66% |
| Sunday Night | 59°F | Showers And Thunderstorms Likely | 7 to 12 mph NE | 67% |
| Monday | 68°F | Showers And Thunderstorms Likely | 10 mph NE | 67% |
| Monday Night | 54°F | Chance Showers And Thunderstorms | 7 to 12 mph NE | 45% |
| Tuesday | 66°F | Chance Rain Showers | 9 mph NE | 31% |
| Tuesday Night | 51°F | Mostly Cloudy | 3 to 8 mph NNE | 5% |
| Wednesday | 69°F | Mostly Sunny | 7 mph NNE | 3% |
| Wednesday Night | 53°F | Mostly Cloudy | 1 to 5 mph NNE | 2% |
| Thursday | 70°F | Mostly Sunny | 1 to 5 mph NNE | 4% |
| Thursday Night | 55°F | Partly Cloudy | 3 mph NNE | 4% |
| Friday | 72°F | Mostly Sunny | 1 to 5 mph NE | 4% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Lewistown, IL
Last spring frost
Apr 17
First fall frost
Oct 19
Growing season
185 days
Hardiness zone
6a
Explore more for Lewistown, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Havana, Il (6.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.