Sullivan, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sullivan, a city in Moultrie County, Illinois.
Tonight
54°F
Rain
Rain before 2am, then rain showers likely. Mostly cloudy. Low around 54, with temperatures rising to around 59 overnight. South wind 13 to 16 mph, with gusts as high as 25 mph. Chance of precipitation is 100%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Sullivan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 54°F | Rain | 13 to 16 mph S | 95% |
| Wednesday | 62°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 14 mph SW | 19% |
| Wednesday Night | 42°F | Mostly Cloudy | 8 mph SW | 0% |
| Thursday | 63°F | Mostly Sunny | 7 to 13 mph WSW | 2% |
| Thursday Night | 41°F | Mostly Cloudy | 5 mph WNW | 9% |
| Friday | 56°F | Mostly Cloudy | 5 to 10 mph NNW | 12% |
| Friday Night | 35°F | Partly Cloudy | 3 to 8 mph NNW | 6% |
| Saturday | 55°F | Mostly Sunny | 5 mph NW | 1% |
| Saturday Night | 32°F | Partly Cloudy | 2 mph W | 2% |
| Sunday | 61°F | Sunny | 2 to 8 mph W | 9% |
| Sunday Night | 32°F | Mostly Clear | 5 mph WNW | 6% |
| Monday | 64°F | Sunny | 3 to 10 mph WSW | 3% |
| Monday Night | 37°F | Mostly Clear | 6 mph WSW | 2% |
| Tuesday | 67°F | Sunny | 7 mph W | 1% |
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 Nov 4, 2026.