St. Augustine, IL Weather & Growing Conditions
Today
86°F
Mostly Cloudy
Mostly cloudy, with a high near 86. Southeast wind around 8 mph. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 86°F | Mostly Cloudy | 8 mph SE | 12% |
| Tonight | 67°F | Showers And Thunderstorms Likely | 1 to 5 mph SSW | 79% |
| Sunday | 74°F | Showers And Thunderstorms Likely | 2 to 13 mph NNE | 72% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms | 10 to 14 mph NE | 63% |
| Monday | 65°F | Showers And Thunderstorms Likely | 15 mph ENE | 63% |
| Monday Night | 53°F | Chance Rain Showers | 9 to 13 mph NE | 49% |
| Tuesday | 63°F | Chance Rain Showers | 13 mph NE | 30% |
| Tuesday Night | 49°F | Partly Cloudy | 5 to 9 mph NNE | 7% |
| Wednesday | 67°F | Mostly Sunny | 8 mph NNE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 1 to 6 mph NNE | 1% |
| Thursday | 69°F | Partly Sunny | 5 mph NNE | 6% |
| Thursday Night | 54°F | Mostly Cloudy | 3 mph NE | 4% |
| Friday | 73°F | Mostly Sunny | 2 to 6 mph NE | 4% |
| Friday Night | 54°F | Partly Cloudy | 3 mph ENE | 4% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for St. Augustine, IL
Last spring frost
Apr 22
First fall frost
Oct 19
Growing season
177 days
Hardiness zone
5b
Explore more for St. Augustine, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Avon, Il (6.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.