Harman US

Alpha, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Alpha, a village in Henry County, Illinois.

This Afternoon
80°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms. Mostly cloudy. High near 80, with temperatures falling to around 78 in the afternoon. South wind 5 to 10 mph. Chance of precipitation is 20%.

7-day forecast for Alpha

WhenTempForecastWindPrecip
This Afternoon 80°F Slight Chance Showers And Thunderstorms 5 to 10 mph S 19%
Tonight 66°F Showers And Thunderstorms 5 mph N 76%
Sunday 70°F Showers And Thunderstorms Likely 5 to 15 mph NE 73%
Sunday Night 58°F Chance Showers And Thunderstorms 15 to 20 mph NE 53%
Monday 63°F Rain Showers Likely 15 mph NE 70%
Monday Night 54°F Rain Showers Likely 10 to 15 mph NE 70%
Tuesday 61°F Chance Rain Showers 15 mph NE 54%
Tuesday Night 50°F Mostly Cloudy 5 to 15 mph NE 8%
Wednesday 64°F Partly Sunny 10 mph NE 3%
Wednesday Night 52°F Partly Cloudy 5 to 10 mph NE 2%
Thursday 67°F Partly Sunny 5 mph NE 3%
Thursday Night 56°F Slight Chance Rain Showers 0 to 5 mph NE 15%
Friday 71°F Partly Sunny 5 mph NE 14%
Friday Night 56°F Partly Cloudy 0 to 5 mph NE 7%

Forecast source: National Weather Service (api.weather.gov) for Alpha (41.192, -90.380). Updated through the day.

Growing snapshot for Alpha

Last spring frost
Apr 28
First fall frost
Oct 12
Growing season
165 days
Hardiness zone
5b

More local growing data for Alpha: nearby ZIP 61413 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, Altona, Il (11.7 mi from Alpha). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.