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
88°F
Mostly Sunny
Mostly sunny, with a high near 88. South wind around 6 mph.
7-day forecast for St. Augustine
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 88°F | Mostly Sunny | 6 mph S | 0% |
| Tonight | 67°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 3 mph SSE | 36% |
| Wednesday | 83°F | Chance Showers And Thunderstorms | 5 mph SSW | 62% |
| Wednesday Night | 64°F | Showers And Thunderstorms | 1 to 5 mph NNW | 85% |
| Thursday | 81°F | Showers And Thunderstorms Likely | 2 mph NE | 73% |
| Thursday Night | 63°F | Partly Cloudy | 1 mph NNE | 8% |
| Friday | 83°F | Mostly Sunny | 0 mph | 8% |
| Friday Night | 65°F | Mostly Clear | 0 mph | 14% |
| Saturday | 86°F | Sunny | 1 to 5 mph SSW | 12% |
| Saturday Night | 69°F | Mostly Clear | 5 mph S | 9% |
| Sunday | 88°F | Sunny | 5 to 10 mph SSW | 8% |
| Sunday Night | 70°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 8 mph S | 24% |
| Monday | 88°F | Slight Chance Showers And Thunderstorms | 5 to 9 mph SSW | 24% |
| Monday Night | 71°F | Slight Chance Showers And Thunderstorms | 7 mph SW | 29% |
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 Aug 4, 2026.