St. Augustine, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for St. Augustine, a village in Knox County, Illinois.
This Afternoon
84°F
Mostly Cloudy
Mostly cloudy, with a high near 84. South southwest wind around 8 mph, with gusts as high as 16 mph.
7-day forecast for St. Augustine
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 84°F | Mostly Cloudy | 8 mph SSW | 7% |
| Tonight | 67°F | Chance Showers And Thunderstorms | 2 to 8 mph SSW | 60% |
| Sunday | 74°F | Showers And Thunderstorms Likely | 3 to 13 mph N | 67% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 10 to 14 mph NE | 59% |
| Monday | 65°F | Showers And Thunderstorms | 13 mph ENE | 75% |
| Monday Night | 54°F | Rain Showers Likely | 10 mph NE | 66% |
| Tuesday | 63°F | Chance Rain Showers | 12 mph NE | 53% |
| Tuesday Night | 50°F | Mostly Cloudy | 3 to 9 mph NNE | 8% |
| Wednesday | 66°F | Partly Sunny | 5 to 8 mph NNE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 1 to 6 mph NNE | 1% |
| Thursday | 69°F | Partly Sunny | 1 to 5 mph NE | 3% |
| Thursday Night | 55°F | Slight Chance Rain Showers | 0 to 3 mph NE | 15% |
| Friday | 73°F | Slight Chance Rain Showers then Partly Sunny | 1 to 5 mph NE | 15% |
| Friday Night | 55°F | Partly Cloudy | 3 mph NE | 7% |
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 20, 2026.