Simpson, IL Weather & Growing Conditions
Today
99°F
Sunny
Sunny. High near 99, with temperatures falling to around 97 in the afternoon. West southwest wind 3 to 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 99°F | Sunny | 3 to 7 mph WSW | 1% |
| Tonight | 72°F | Mostly Clear | 3 mph SSW | 1% |
| Sunday | 97°F | Mostly Sunny | 1 to 7 mph SW | 2% |
| Sunday Night | 69°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 0 to 3 mph NNE | 19% |
| Monday | 91°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 2 to 6 mph NE | 30% |
| Monday Night | 64°F | Chance Showers And Thunderstorms | 2 to 6 mph NNE | 30% |
| Tuesday | 80°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 5 to 9 mph N | 29% |
| Tuesday Night | 59°F | Partly Cloudy | 2 to 9 mph N | 11% |
| Wednesday | 78°F | Mostly Sunny | 7 mph N | 3% |
| Wednesday Night | 56°F | Partly Cloudy | 1 to 6 mph N | 0% |
| Thursday | 79°F | Mostly Sunny | 2 to 6 mph N | 1% |
| Thursday Night | 58°F | Partly Cloudy | 0 to 3 mph NNE | 1% |
| Friday | 80°F | Partly Sunny | 0 to 6 mph NNE | 4% |
| Friday Night | 59°F | Partly Cloudy | 1 to 5 mph NNE | 4% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Simpson, IL
Last spring frost
Apr 14
First fall frost
Oct 21
Growing season
189 days
Hardiness zone
7a
Explore more for Simpson, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Dixon Springs Agric Ctr, Il (2.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.