Marengo, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Marengo, a city in Mchenry County, Illinois.
Overnight
58°F
Chance Rain Showers
A chance of rain showers. Cloudy. Low around 58, with temperatures rising to around 60 overnight. South wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Marengo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 58°F | Chance Rain Showers | 15 mph S | 41% |
| Wednesday | 62°F | Patchy Drizzle | 15 mph SSW | 23% |
| Wednesday Night | 46°F | Patchy Drizzle | 15 mph SW | 21% |
| Thursday | 55°F | Chance Rain Showers | 10 to 15 mph WSW | 35% |
| Thursday Night | 39°F | Chance Rain Showers then Mostly Cloudy | 10 mph NW | 44% |
| Friday | 48°F | Partly Sunny | 10 to 15 mph N | 9% |
| Friday Night | 31°F | Partly Cloudy | 0 to 10 mph NNW | 0% |
| Saturday | 51°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 32°F | Mostly Clear | 0 mph | 1% |
| Sunday | 55°F | Sunny | 5 to 10 mph W | 6% |
| Sunday Night | 34°F | Mostly Clear | 0 to 5 mph W | 0% |
| Monday | 61°F | Sunny | 0 to 10 mph WSW | 0% |
| Monday Night | 39°F | Partly Cloudy | 0 to 5 mph WSW | 1% |
| Tuesday | 61°F | Sunny | 0 to 5 mph WNW | 0% |
Forecast source: National Weather Service (api.weather.gov) for Marengo (42.247, -88.598). Updated through the day.
Growing snapshot for Marengo
Last spring frost
Apr 28
First fall frost
Oct 12
Growing season
166 days
Hardiness zone
5b
More local growing data for Marengo: nearby ZIP 60152 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Algonquin
Bull Valley
Cary
Chemung
Coral
Crystal Lake
Fox River Grove
Franklinville
Greenwood
Harmony
Hartland
Harvard
Hebron
Huntley
Johnsburg
Lake Barrington
Lake in the Hills
Lakemoor
Lakewood
Lawrence
McCullom Lake
McHenry
Oakwood Hills
Prairie Grove
Richmond
Ridgefield
Riley
Ringwood
Solon Mills
Spring Grove
Climate data from the nearest NOAA station, Marengo, Il (2 mi from Marengo). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.