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 4am, then patchy fog and showers and thunderstorms likely. Mostly cloudy, with a low around 63. Southeast wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Savanna
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 63°F | Chance Showers And Thunderstorms | 5 mph SE | 69% |
| Saturday | 79°F | Patchy Fog | 5 to 10 mph SE | 96% |
| Saturday Night | 61°F | Showers And Thunderstorms | 5 to 10 mph NE | 90% |
| Sunday | 69°F | Rain Showers Likely | 10 to 15 mph NE | 55% |
| Sunday Night | 54°F | Chance Rain Showers | 10 to 15 mph NE | 35% |
| Monday | 65°F | Chance Rain Showers | 10 to 15 mph NE | 47% |
| Monday Night | 49°F | Chance Rain Showers | 10 to 15 mph NE | 30% |
| Tuesday | 63°F | Slight Chance Rain Showers then Partly Sunny | 10 mph NE | 20% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 10 mph NE | 6% |
| Wednesday | 67°F | Mostly Sunny | 5 to 10 mph NE | 1% |
| Wednesday Night | 49°F | Partly Cloudy | 0 to 5 mph NE | 1% |
| Thursday | 68°F | Mostly Sunny | 5 mph NE | 5% |
| Thursday Night | 50°F | Partly Cloudy | 0 to 5 mph NE | 5% |
| Friday | 71°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.