St. Augustine, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Augustine, a village in Knox County, Illinois.
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 for St. Augustine
| 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 SW | 78% |
| 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 | 64% |
| Monday | 65°F | Showers And Thunderstorms Likely | 14 mph ENE | 64% |
| Monday Night | 53°F | Chance Rain Showers | 8 to 13 mph NE | 49% |
| Tuesday | 63°F | Chance Rain Showers | 9 to 13 mph NE | 28% |
| Tuesday Night | 49°F | Partly Cloudy | 3 to 9 mph NNE | 7% |
| Wednesday | 67°F | Mostly Sunny | 5 to 8 mph NNE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 1 to 6 mph NNE | 1% |
| Thursday | 70°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) for St. Augustine (40.721, -90.407). Updated through the day.
Growing snapshot for St. Augustine
Last spring frost
Apr 22
First fall frost
Oct 19
Growing season
177 days
Hardiness zone
5b
More local growing data for St. Augustine: nearby ZIP 61474 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Abingdon
Altona
East Galesburg
Galesburg
Gilson
Henderson
Knoxville
Maquon
Nekoma
Oak Run
Oneida
Rio
Victoria
Wataga
Williamsfield
Yates City
Climate data from the nearest NOAA station, Avon, Il (6.1 mi from St. Augustine). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.