Simpson, IL Weather & Growing Conditions
Tonight
57°F
Showers And Thunderstorms
Showers and thunderstorms before 4am. Mostly cloudy. Low around 57, with temperatures rising to around 59 overnight. South wind 6 to 12 mph, with gusts as high as 23 mph. Chance of precipitation is 100%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 57°F | Showers And Thunderstorms | 6 to 12 mph S | 99% |
| Wednesday | 70°F | Partly Sunny | 5 to 9 mph SW | 8% |
| Wednesday Night | 44°F | Partly Cloudy | 2 mph SW | 0% |
| Thursday | 70°F | Sunny | 0 to 8 mph SW | 0% |
| Thursday Night | 45°F | Partly Cloudy | 1 mph NW | 4% |
| Friday | 63°F | Partly Sunny | 1 to 8 mph NNW | 4% |
| Friday Night | 40°F | Mostly Cloudy | 1 to 5 mph NNW | 1% |
| Saturday | 58°F | Mostly Sunny | 5 mph NNW | 0% |
| Saturday Night | 35°F | Partly Cloudy | 1 mph NNW | 1% |
| Sunday | 62°F | Sunny | 0 to 5 mph WNW | 5% |
| Sunday Night | 34°F | Mostly Clear | 2 mph NNW | 6% |
| Monday | 65°F | Sunny | 1 to 6 mph WNW | 2% |
| Monday Night | 38°F | Mostly Clear | 2 mph W | 0% |
| Tuesday | 69°F | Sunny | 1 to 5 mph WSW | 0% |
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 Nov 4, 2026.