Johnston City, IL Weather & Growing Conditions
Overnight
57°F
Rain Showers Likely
Rain showers likely before 3am. Mostly cloudy. Low around 57, with temperatures rising to around 59 overnight. South southwest wind around 10 mph, with gusts as high as 18 mph. Chance of precipitation is 60%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 57°F | Rain Showers Likely | 10 mph SSW | 64% |
| Wednesday | 67°F | Partly Sunny | 5 to 10 mph WSW | 10% |
| Wednesday Night | 44°F | Mostly Clear | 3 mph WSW | 0% |
| Thursday | 69°F | Sunny | 3 to 8 mph WSW | 0% |
| Thursday Night | 45°F | Partly Cloudy | 2 mph WNW | 1% |
| Friday | 61°F | Partly Sunny | 3 to 12 mph NNW | 0% |
| Friday Night | 36°F | Partly Cloudy | 2 to 8 mph N | 0% |
| Saturday | 57°F | Mostly Sunny | 2 to 6 mph N | 0% |
| Saturday Night | 34°F | Partly Cloudy | 1 mph NNW | 0% |
| Sunday | 62°F | Sunny | 1 to 7 mph NW | 0% |
| Sunday Night | 34°F | Clear | 2 mph NW | 1% |
| Monday | 66°F | Sunny | 0 to 7 mph WSW | 0% |
| Monday Night | 38°F | Clear | 2 mph SW | 1% |
| Tuesday | 70°F | Sunny | 1 to 6 mph WSW | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Johnston City, IL
Last spring frost
Apr 4
First fall frost
Oct 28
Growing season
206 days
Hardiness zone
7a
Explore more for Johnston City, IL: full frost dates · planting calendar · Illinois frost dates
Climate data from the nearest NOAA station, Benton 2 N, Il (14.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.