Riley, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Riley, a community in Mchenry County, Illinois.
This Afternoon
68°F
Rain
Rain and a slight chance of thunderstorms. Mostly cloudy. High near 68, with temperatures falling to around 66 in the afternoon. South wind around 15 mph, with gusts as high as 35 mph. Chance of precipitation is 80%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Riley
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 68°F | Rain | 15 mph S | 76% |
| Tonight | 58°F | Rain | 15 mph S | 88% |
| Wednesday | 61°F | Rain Likely | 15 mph SSW | 55% |
| Wednesday Night | 47°F | Chance Rain | 15 mph SW | 31% |
| Thursday | 55°F | Chance Rain | 10 to 15 mph WSW | 46% |
| Thursday Night | 41°F | Chance Rain | 5 to 10 mph NW | 46% |
| Friday | 51°F | Slight Chance Rain then Mostly Cloudy | 10 mph N | 20% |
| Friday Night | 34°F | Partly Cloudy | 0 to 5 mph NNW | 3% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph WNW | 3% |
| Saturday Night | 33°F | Partly Cloudy | 0 to 5 mph WSW | 5% |
| Sunday | 57°F | Mostly Sunny then Slight Chance Rain | 5 to 10 mph W | 16% |
| Sunday Night | 35°F | Mostly Clear | 0 to 5 mph W | 5% |
| Monday | 60°F | Sunny | 5 to 15 mph WSW | 2% |
| Monday Night | 39°F | Mostly Clear | 5 to 10 mph W | 1% |
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 Nov 3, 2026.