Sullivan, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sullivan, a city in Moultrie County, Illinois.
Tonight
69°F
Partly Cloudy
Partly cloudy, with a low around 69. Southeast wind around 7 mph.
7-day forecast for Sullivan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 69°F | Partly Cloudy | 7 mph SE | 9% |
| Saturday | 92°F | Chance Showers And Thunderstorms | 6 to 10 mph SSW | 29% |
| Saturday Night | 70°F | Mostly Cloudy then Slight Chance Showers And Thunderstorms | 5 to 8 mph S | 15% |
| Sunday | 88°F | Chance Showers And Thunderstorms | 3 to 9 mph NW | 29% |
| Sunday Night | 61°F | Showers And Thunderstorms Likely | 10 mph NE | 61% |
| Monday | 73°F | Showers And Thunderstorms Likely | 13 mph NE | 65% |
| Monday Night | 55°F | Showers And Thunderstorms Likely | 9 to 13 mph NE | 60% |
| Tuesday | 70°F | Chance Showers And Thunderstorms then Mostly Cloudy | 13 mph NE | 32% |
| Tuesday Night | 52°F | Mostly Cloudy | 6 to 12 mph NNE | 8% |
| Wednesday | 72°F | Partly Sunny | 7 to 10 mph NNE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 3 to 9 mph NNE | 2% |
| Thursday | 73°F | Mostly Sunny | 5 to 9 mph NNE | 3% |
| Thursday Night | 54°F | Partly Cloudy | 3 to 7 mph NNE | 4% |
| Friday | 75°F | Mostly Sunny | 5 to 9 mph NNE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Sullivan (39.595, -88.609). Updated through the day.
Growing snapshot for Sullivan
Last spring frost
Apr 15
First fall frost
Oct 22
Growing season
187 days
Hardiness zone
6a
More local growing data for Sullivan: nearby ZIP 61951 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Sullivan 3S, Il (2.6 mi from Sullivan). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.