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
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| 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
Nearby towns & communities
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.