Princeton, IL Weather & Growing Conditions
Overnight
54°F
Slight Chance Rain Showers
A slight chance of rain showers. Mostly cloudy. Low around 54, with temperatures rising to around 57 overnight. South wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 54°F | Slight Chance Rain Showers | 10 mph S | 22% |
| Wednesday | 59°F | Chance Rain Showers then Mostly Cloudy | 10 to 15 mph SW | 30% |
| Wednesday Night | 46°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph SW | 18% |
| Thursday | 55°F | Chance Rain Showers | 10 to 15 mph W | 38% |
| Thursday Night | 42°F | Chance Rain Showers then Mostly Cloudy | 5 to 10 mph NW | 26% |
| Friday | 50°F | Partly Sunny | 5 to 10 mph N | 5% |
| Friday Night | 32°F | Partly Cloudy | 0 to 5 mph N | 0% |
| Saturday | 52°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 33°F | Mostly Clear | 0 to 5 mph W | 1% |
| Sunday | 57°F | Sunny | 5 to 10 mph W | 3% |
| Sunday Night | 34°F | Clear | 0 to 5 mph W | 1% |
| Monday | 62°F | Sunny | 0 to 10 mph SW | 0% |
| Monday Night | 39°F | Mostly Clear | 5 mph W | 0% |
| Tuesday | 62°F | Sunny | 5 mph NW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Princeton, IL
Last spring frost
Apr 22
First fall frost
Oct 17
Growing season
177 days
Hardiness zone
5b
Explore more for Princeton, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Princeton, Il (1.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.