Savanna, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Savanna, a city in Carroll County, Illinois.
Overnight
61°F
Mostly Clear
Mostly clear, with a low around 61. South wind around 5 mph.
7-day forecast for Savanna
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 61°F | Mostly Clear | 5 mph S | 0% |
| Tuesday | 85°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 19% |
| Tuesday Night | 65°F | Showers And Thunderstorms Likely | 0 to 5 mph NW | 78% |
| Wednesday | 76°F | Showers And Thunderstorms Likely | 0 to 5 mph N | 71% |
| Wednesday Night | 59°F | Showers And Thunderstorms Likely | 0 to 5 mph N | 64% |
| Thursday | 79°F | Chance Rain Showers then Mostly Sunny | 0 to 5 mph NE | 27% |
| Thursday Night | 59°F | Mostly Clear | 0 mph | 5% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph S | 4% |
| Friday Night | 63°F | Mostly Clear | 0 mph | 8% |
| Saturday | 85°F | Sunny | 0 to 5 mph SW | 11% |
| Saturday Night | 69°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 mph S | 22% |
| Sunday | 86°F | Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 22% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 40% |
| Monday | 85°F | Chance Showers And Thunderstorms | 5 to 10 mph S | 39% |
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 Aug 4, 2026.