Pittsburg, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Pittsburg, a village in Williamson County, Illinois.
Tonight
71°F
Slight Chance Showers And Thunderstorms then Partly Cloudy
A slight chance of showers and thunderstorms before 9pm. Partly cloudy. Low around 71, with temperatures rising to around 73 overnight. Southeast wind around 1 mph. Chance of precipitation is 20%.
7-day forecast for Pittsburg
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 71°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 1 mph SE | 18% |
| Saturday | 98°F | Sunny | 2 to 8 mph SW | 4% |
| Saturday Night | 73°F | Partly Cloudy | 5 mph SSW | 2% |
| Sunday | 97°F | Sunny | 3 to 9 mph WSW | 7% |
| Sunday Night | 70°F | Partly Cloudy | 2 to 6 mph N | 13% |
| Monday | 88°F | Partly Sunny then Chance Showers And Thunderstorms | 3 to 10 mph N | 43% |
| Monday Night | 63°F | Chance Showers And Thunderstorms | 6 to 12 mph NNE | 43% |
| Tuesday | 76°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 8 to 13 mph N | 20% |
| Tuesday Night | 57°F | Mostly Cloudy | 5 to 13 mph N | 7% |
| Wednesday | 76°F | Mostly Sunny | 6 to 10 mph N | 3% |
| Wednesday Night | 56°F | Partly Cloudy | 3 to 9 mph NNE | 2% |
| Thursday | 77°F | Mostly Sunny | 3 to 10 mph NNE | 2% |
| Thursday Night | 58°F | Partly Cloudy | 2 to 8 mph NNE | 2% |
| Friday | 77°F | Mostly Sunny | 5 to 10 mph NNE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Pittsburg (37.777, -88.850). Updated through the day.
Growing snapshot for Pittsburg
Last spring frost
Apr 7
First fall frost
Oct 26
Growing season
202 days
Hardiness zone
7a
More local growing data for Pittsburg: nearby ZIP 62974 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Blairsville
Bush
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Carterville
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Crainville
Creal Springs
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Freeman Spur
Herrin
Hurst
Johnston City
Marion
Spillertown
Whiteash
Climate data from the nearest NOAA station, Harrisburg, Il (15.1 mi from Pittsburg). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.