Algonquin, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Algonquin, a village in Mchenry County, Illinois.
Tonight
61°F
Mostly Cloudy then Showers And Thunderstorms Likely
Showers and thunderstorms likely after midnight. Mostly cloudy, with a low around 61. 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 Algonquin
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 61°F | Mostly Cloudy then Showers And Thunderstorms Likely | 10 mph E | 62% |
| Saturday | 75°F | Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph SE | 93% |
| Saturday Night | 62°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 to 10 mph NE | 80% |
| Sunday | 67°F | Showers And Thunderstorms | 10 to 15 mph NE | 75% |
| Sunday Night | 55°F | Chance Rain Showers | 15 mph ENE | 49% |
| Monday | 63°F | Chance Rain Showers | 15 mph ENE | 42% |
| Monday Night | 51°F | Chance Rain Showers | 10 to 15 mph ENE | 39% |
| Tuesday | 62°F | Slight Chance Rain Showers | 10 to 15 mph NE | 19% |
| Tuesday Night | 50°F | Mostly Cloudy | 5 to 10 mph NE | 14% |
| Wednesday | 64°F | Partly Sunny | 5 to 10 mph NNE | 9% |
| Wednesday Night | 51°F | Mostly Cloudy | 0 to 5 mph NNE | 4% |
| Thursday | 68°F | Partly Sunny | 0 to 5 mph NNE | 5% |
| Thursday Night | 52°F | Mostly Cloudy | 0 to 5 mph NNE | 4% |
| Friday | 69°F | Mostly Sunny | 0 to 5 mph NNE | 5% |
Forecast source: National Weather Service (api.weather.gov) for Algonquin (42.159, -88.322). Updated through the day.
Growing snapshot for Algonquin
Last spring frost
Apr 26
First fall frost
Oct 18
Growing season
174 days
Hardiness zone
5b
More local growing data for Algonquin: nearby ZIP 60102 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Bull Valley
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Greenwood
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Huntley
Johnsburg
Lake Barrington
Lake in the Hills
Lakemoor
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Lawrence
Marengo
McCullom Lake
McHenry
Oakwood Hills
Prairie Grove
Richmond
Ridgefield
Riley
Ringwood
Solon Mills
Spring Grove
Climate data from the nearest NOAA station, Elgin, Il (7 mi from Algonquin). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.