Harristown, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Harristown, a village in Macon County, Illinois.
This Afternoon
73°F
Light Rain Likely
Rain likely and a slight chance of thunderstorms. Mostly cloudy. High near 73, with temperatures falling to around 68 in the afternoon. South southeast wind around 22 mph, with gusts as high as 35 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Harristown
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 73°F | Light Rain Likely | 22 mph SSE | 62% |
| Tonight | 54°F | Rain | 15 to 20 mph S | 83% |
| Wednesday | 60°F | Slight Chance Light Rain then Mostly Cloudy | 13 to 17 mph SW | 19% |
| Wednesday Night | 44°F | Mostly Cloudy | 12 mph SW | 1% |
| Thursday | 61°F | Mostly Sunny | 10 to 16 mph WSW | 4% |
| Thursday Night | 42°F | Mostly Cloudy then Slight Chance Light Rain | 5 to 8 mph NW | 22% |
| Friday | 55°F | Mostly Cloudy | 7 to 13 mph NNW | 13% |
| Friday Night | 36°F | Mostly Cloudy | 2 to 10 mph NNW | 6% |
| Saturday | 53°F | Mostly Sunny | 2 to 6 mph NW | 1% |
| Saturday Night | 33°F | Partly Cloudy | 3 mph W | 2% |
| Sunday | 59°F | Sunny | 2 to 10 mph W | 9% |
| Sunday Night | 34°F | Mostly Clear | 3 to 7 mph WNW | 5% |
| Monday | 63°F | Sunny | 3 to 12 mph SW | 3% |
| Monday Night | 39°F | Mostly Clear | 5 to 8 mph WSW | 2% |
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 Nov 4, 2026.