Harristown, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Harristown, a village in Macon County, Illinois.
This Afternoon
87°F
Mostly Sunny
Mostly sunny. High near 87, with temperatures falling to around 82 in the afternoon. East northeast wind around 9 mph.
7-day forecast for Harristown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 87°F | Mostly Sunny | 9 mph ENE | 11% |
| Tonight | 70°F | Partly Cloudy | 9 mph ESE | 6% |
| Saturday | 91°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 9 mph SSW | 18% |
| Saturday Night | 69°F | Partly Cloudy then Slight Chance Rain Showers | 8 mph SSW | 23% |
| Sunday | 85°F | Chance Rain Showers | 3 to 12 mph NNW | 49% |
| Sunday Night | 61°F | Chance Showers And Thunderstorms | 14 mph NE | 68% |
| Monday | 71°F | Showers And Thunderstorms Likely | 16 mph NE | 68% |
| Monday Night | 55°F | Showers And Thunderstorms Likely | 12 to 16 mph NE | 64% |
| Tuesday | 68°F | Chance Rain Showers | 15 mph NE | 35% |
| Tuesday Night | 52°F | Mostly Cloudy | 7 to 14 mph NNE | 7% |
| Wednesday | 70°F | Partly Sunny | 12 mph NNE | 2% |
| Wednesday Night | 53°F | Partly Cloudy | 5 to 10 mph NNE | 2% |
| Thursday | 72°F | Mostly Sunny | 5 to 10 mph NNE | 3% |
| Thursday Night | 55°F | Partly Cloudy | 3 to 9 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov) for Harristown (39.843, -89.061). Updated through the day.
Growing snapshot for Harristown
Last spring frost
Apr 14
First fall frost
Oct 24
Growing season
192 days
Hardiness zone
6a
More local growing data for Harristown: nearby ZIP 62522 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Argenta
Boody
Dalton City
Decatur
Elwin
Forsyth
Long Creek
Macon
Maroa
Mount Zion
Niantic
Oreana
Warrensburg
Climate data from the nearest NOAA station, Decatur Wtp, Il (5.2 mi from Harristown). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.