Riley, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Riley, a community in Mchenry County, Illinois.
Tonight
62°F
Mostly Cloudy then Showers And Thunderstorms Likely
Showers and thunderstorms likely after midnight. Some of the storms could produce heavy rain. Mostly cloudy, with a low around 62. East wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 60%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Riley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 62°F | Mostly Cloudy then Showers And Thunderstorms Likely | 10 mph E | 63% |
| Saturday | 76°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 92% |
| Saturday Night | 62°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 to 10 mph NE | 78% |
| Sunday | 67°F | Showers And Thunderstorms Likely | 10 to 15 mph NE | 73% |
| Sunday Night | 54°F | Chance Rain Showers | 10 to 15 mph NE | 50% |
| Monday | 64°F | Chance Rain Showers | 15 mph ENE | 39% |
| Monday Night | 50°F | Chance Rain Showers | 10 to 15 mph NE | 39% |
| Tuesday | 62°F | Slight Chance Rain Showers | 10 to 15 mph NE | 20% |
| Tuesday Night | 49°F | Mostly Cloudy | 5 to 10 mph NE | 12% |
| Wednesday | 66°F | Partly Sunny | 5 to 10 mph NE | 6% |
| Wednesday Night | 50°F | Mostly Cloudy | 0 to 10 mph NNE | 4% |
| Thursday | 68°F | Partly Sunny | 0 to 5 mph NNE | 4% |
| Thursday Night | 51°F | Mostly Cloudy | 0 to 5 mph NNE | 4% |
| Friday | 70°F | Mostly Sunny | 0 to 5 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov) for Riley (42.193, -88.629). Updated through the day.
Growing snapshot for Riley
Last spring frost
Apr 28
First fall frost
Oct 12
Growing season
166 days
Hardiness zone
5b
More local growing data for Riley: nearby ZIP 60152 weather · frost dates · planting calendar · Illinois frost dates
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Climate data from the nearest NOAA station, Marengo, Il (2 mi from Riley). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.