Oswego, IL Weather & Growing Conditions
Today
84°F
Mostly Sunny
Mostly sunny, with a high near 84. South wind 5 to 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Mostly Sunny | 5 to 10 mph S | 3% |
| Tonight | 67°F | Mostly Cloudy then Chance Showers And Thunderstorms | 5 mph S | 30% |
| Wednesday | 80°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 5 mph WSW | 69% |
| Wednesday Night | 65°F | Showers And Thunderstorms | 5 mph NW | 88% |
| Thursday | 79°F | Rain Showers Likely then Chance Showers And Thunderstorms | 5 mph ESE | 67% |
| Thursday Night | 62°F | Chance Showers And Thunderstorms then Partly Cloudy | 0 to 5 mph SSE | 29% |
| Friday | 82°F | Mostly Sunny | 0 to 5 mph SE | 6% |
| Friday Night | 64°F | Mostly Clear | 0 to 5 mph S | 9% |
| Saturday | 84°F | Mostly Sunny | 5 to 10 mph SSW | 11% |
| Saturday Night | 69°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 10 mph SSW | 17% |
| Sunday | 86°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 to 15 mph SW | 17% |
| Sunday Night | 70°F | Chance Showers And Thunderstorms | 5 to 15 mph SSW | 36% |
| Monday | 85°F | Chance Rain Showers | 5 to 10 mph SSW | 36% |
| Monday Night | 69°F | Chance Showers And Thunderstorms | 10 mph W | 43% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Oswego, IL
Last spring frost
Apr 19
First fall frost
Oct 23
Growing season
185 days
Hardiness zone
5b
Explore more for Oswego, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Aurora, Il (7.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.