Lewistown, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Lewistown, a city in Fulton County, Illinois.
Today
89°F
Mostly Sunny
Mostly sunny, with a high near 89. South wind around 5 mph.
7-day forecast for Lewistown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 89°F | Mostly Sunny | 5 mph S | 0% |
| Tonight | 68°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 3 mph SSE | 16% |
| Wednesday | 86°F | Chance Showers And Thunderstorms | 5 mph SSW | 45% |
| Wednesday Night | 66°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 3 mph N | 87% |
| Thursday | 82°F | Showers And Thunderstorms | 2 mph SSE | 80% |
| Thursday Night | 64°F | Partly Cloudy | 1 mph SE | 11% |
| Friday | 84°F | Mostly Sunny | 0 mph | 6% |
| Friday Night | 66°F | Slight Chance Showers And Thunderstorms | 0 mph | 17% |
| Saturday | 87°F | Slight Chance Showers And Thunderstorms then Sunny | 0 to 3 mph SSW | 16% |
| Saturday Night | 70°F | Mostly Clear | 3 mph SSW | 9% |
| Sunday | 89°F | Sunny | 5 to 9 mph SSW | 5% |
| Sunday Night | 71°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 3 to 7 mph SSW | 17% |
| Monday | 89°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 5 to 8 mph SSW | 17% |
| Monday Night | 71°F | Slight Chance Showers And Thunderstorms | 6 mph SW | 28% |
Forecast source: National Weather Service (api.weather.gov) for Lewistown (40.397, -90.156). Updated through the day.
Growing snapshot for Lewistown
Last spring frost
Apr 17
First fall frost
Oct 19
Growing season
185 days
Hardiness zone
6a
More local growing data for Lewistown: nearby ZIP 61542 weather · frost dates · planting calendar · Illinois frost dates
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Vermont
Climate data from the nearest NOAA station, Havana, Il (6.2 mi from Lewistown). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.