Raritan, IL Weather & Growing Conditions
Tonight
51°F
Mostly Cloudy
Mostly cloudy. Low around 51, with temperatures rising to around 54 overnight. Southwest wind 10 to 15 mph, with gusts as high as 25 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 51°F | Mostly Cloudy | 10 to 15 mph SW | 9% |
| Wednesday | 56°F | Slight Chance Rain Showers | 15 mph W | 16% |
| Wednesday Night | 45°F | Mostly Cloudy | 10 to 15 mph SW | 6% |
| Thursday | 55°F | Slight Chance Rain Showers | 10 to 15 mph W | 21% |
| Thursday Night | 43°F | Chance Rain Showers | 10 mph NW | 29% |
| Friday | 51°F | Partly Sunny | 5 to 10 mph N | 8% |
| Friday Night | 32°F | Partly Cloudy | 0 to 5 mph N | 0% |
| Saturday | 52°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 34°F | Mostly Clear | 0 to 5 mph W | 1% |
| Sunday | 57°F | Sunny | 5 mph W | 2% |
| Sunday Night | 36°F | Clear | 0 to 5 mph W | 0% |
| Monday | 63°F | Sunny | 0 to 10 mph SW | 0% |
| Monday Night | 41°F | Mostly Clear | 5 mph W | 0% |
| Tuesday | 64°F | Sunny | 5 mph NW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Raritan, IL
Last spring frost
Apr 21
First fall frost
Oct 19
Growing season
180 days
Explore more for Raritan, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, La Harpe, Il (10.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.