Swansea, IL Weather & Growing Conditions
Today
87°F
Sunny
Sunny, with a high near 87. South wind around 6 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Sunny | 6 mph S | 0% |
| Tonight | 68°F | Mostly Clear | 2 to 6 mph SE | 0% |
| Wednesday | 90°F | Sunny | 2 to 6 mph S | 6% |
| Wednesday Night | 72°F | Slight Chance Showers And Thunderstorms | 7 mph S | 61% |
| Thursday | 88°F | Showers And Thunderstorms Likely | 6 mph S | 70% |
| Thursday Night | 71°F | Chance Showers And Thunderstorms | 5 mph SE | 44% |
| Friday | 88°F | Chance Showers And Thunderstorms | 5 mph SW | 44% |
| Friday Night | 71°F | Chance Showers And Thunderstorms | 3 mph SW | 36% |
| Saturday | 90°F | Chance Showers And Thunderstorms then Mostly Sunny | 5 mph S | 36% |
| Saturday Night | 73°F | Partly Cloudy | 6 mph S | 8% |
| Sunday | 92°F | Sunny | 5 to 8 mph S | 7% |
| Sunday Night | 74°F | Mostly Clear | 6 to 9 mph S | 5% |
| Monday | 94°F | Sunny | 8 mph SW | 5% |
| Monday Night | 76°F | Slight Chance Showers And Thunderstorms | 9 mph SW | 15% |
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 Aug 4, 2026.