Harmony, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Harmony, a community in Mchenry County, Illinois.
Overnight
62°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely before 4am, then showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy. Low around 62, with temperatures rising to around 64 overnight. East southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Harmony
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 62°F | Showers And Thunderstorms Likely | 10 mph ESE | 87% |
| Saturday | 76°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 100% |
| Saturday Night | 62°F | Showers And Thunderstorms | 5 to 10 mph E | 93% |
| Sunday | 68°F | Showers And Thunderstorms Likely | 10 to 15 mph NE | 56% |
| Sunday Night | 55°F | Slight Chance Rain Showers | 15 mph NE | 20% |
| Monday | 63°F | Chance Rain Showers | 15 mph ENE | 32% |
| Monday Night | 50°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 17% |
| Tuesday | 62°F | Mostly Cloudy | 10 to 15 mph NE | 13% |
| Tuesday Night | 49°F | Partly Cloudy | 5 to 15 mph NE | 9% |
| Wednesday | 64°F | Partly Sunny | 5 to 15 mph NE | 6% |
| Wednesday Night | 51°F | Mostly Cloudy | 5 to 10 mph NNE | 2% |
| Thursday | 66°F | Partly Sunny | 5 to 10 mph NNE | 4% |
| Thursday Night | 51°F | Mostly Cloudy | 0 to 5 mph NE | 4% |
| Friday | 70°F | Mostly Sunny | 0 to 10 mph NE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Harmony (42.159, -88.529). Updated through the day.
Growing snapshot for Harmony
Last spring frost
Apr 28
First fall frost
Oct 12
Growing season
166 days
Hardiness zone
5b
More local growing data for Harmony: nearby ZIP 60180 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Algonquin
Bull Valley
Cary
Chemung
Coral
Crystal Lake
Fox River Grove
Franklinville
Greenwood
Hartland
Harvard
Hebron
Huntley
Johnsburg
Lake Barrington
Lake in the Hills
Lakemoor
Lakewood
Lawrence
Marengo
McCullom Lake
McHenry
Oakwood Hills
Prairie Grove
Richmond
Ridgefield
Riley
Ringwood
Solon Mills
Spring Grove
Climate data from the nearest NOAA station, Marengo, Il (5.3 mi from Harmony). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.