Swansea, IL Weather & Growing Conditions
Tonight
56°F
Rain
Rain and a slight chance of thunderstorms before 3am, then a slight chance of drizzle. Cloudy, with a low around 56. South wind 7 to 15 mph, with gusts as high as 32 mph. Chance of precipitation is 90%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 56°F | Rain | 7 to 15 mph S | 92% |
| Wednesday | 64°F | Slight Chance Drizzle then Mostly Cloudy | 7 to 13 mph W | 10% |
| Wednesday Night | 46°F | Partly Cloudy | 5 mph SW | 0% |
| Thursday | 66°F | Sunny | 5 to 9 mph W | 1% |
| Thursday Night | 47°F | Mostly Cloudy | 5 mph NW | 8% |
| Friday | 58°F | Mostly Cloudy | 5 to 10 mph NW | 6% |
| Friday Night | 41°F | Partly Cloudy | 2 to 7 mph N | 1% |
| Saturday | 56°F | Partly Sunny | 5 mph NW | 0% |
| Saturday Night | 39°F | Partly Cloudy | 2 mph NW | 0% |
| Sunday | 62°F | Sunny | 2 to 7 mph W | 8% |
| Sunday Night | 39°F | Mostly Clear | 5 mph W | 5% |
| Monday | 66°F | Sunny | 2 to 7 mph SW | 2% |
| Monday Night | 43°F | Mostly Clear | 3 mph SW | 1% |
| Tuesday | 69°F | Sunny | 6 mph W | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Swansea, IL
Last spring frost
Apr 12
First fall frost
Oct 20
Growing season
189 days
Hardiness zone
7a
Explore more for Swansea, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Belleville Siu Rsch, Il (8.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.