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Savanna, IL Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Savanna, a city in Carroll County, Illinois.

Overnight
63°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 3am, then showers and thunderstorms. Some of the storms could produce heavy rain. Mostly cloudy. Low around 63, with temperatures rising to around 65 overnight. Southeast wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

7-day forecast for Savanna

WhenTempForecastWindPrecip
Overnight 63°F Chance Showers And Thunderstorms 5 to 10 mph SE 79%
Saturday 80°F Showers And Thunderstorms Likely 5 mph SE 80%
Saturday Night 61°F Showers And Thunderstorms 5 mph N 75%
Sunday 69°F Rain Showers 10 to 15 mph NE 75%
Sunday Night 53°F Rain Showers Likely 10 to 15 mph NE 60%
Monday 65°F Chance Rain Showers 10 to 15 mph NE 45%
Monday Night 49°F Chance Rain Showers 10 to 15 mph NE 45%
Tuesday 63°F Chance Rain Showers 10 mph NE 36%
Tuesday Night 47°F Partly Cloudy 5 to 10 mph NE 7%
Wednesday 67°F Mostly Sunny 5 mph NE 3%
Wednesday Night 49°F Partly Cloudy 0 to 5 mph NE 2%
Thursday 69°F Mostly Sunny 0 to 5 mph NE 5%
Thursday Night 51°F Partly Cloudy 0 to 5 mph NE 5%
Friday 70°F Mostly Sunny 0 to 5 mph NE 5%

Forecast source: National Weather Service (api.weather.gov) for Savanna (42.094, -90.139). Updated through the day.

Growing snapshot for Savanna

Last spring frost
May 2
First fall frost
Oct 7
Growing season
154 days
Hardiness zone
5a

More local growing data for Savanna: nearby ZIP 61074 weather · frost dates · planting calendar · Illinois frost dates

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Climate data from the nearest NOAA station, Mt Carroll, Il (7.3 mi from Savanna). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.