Marietta, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Marietta, a village in Fulton County, Illinois.
This Afternoon
69°F
Light Rain Likely
Rain likely and a chance of thunderstorms. Cloudy, with a high near 69. South southeast wind around 17 mph, with gusts as high as 29 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Marietta
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Light Rain Likely | 17 mph SSE | 71% |
| Tonight | 51°F | Light Rain Likely | 10 to 16 mph SSW | 71% |
| Wednesday | 57°F | Chance Rain Showers then Mostly Cloudy | 13 to 16 mph SW | 14% |
| Wednesday Night | 44°F | Mostly Cloudy | 7 to 10 mph SW | 4% |
| Thursday | 57°F | Partly Sunny | 7 to 13 mph W | 13% |
| Thursday Night | 41°F | Mostly Cloudy then Chance Light Rain | 6 mph NW | 29% |
| Friday | 54°F | Mostly Cloudy | 6 to 9 mph N | 13% |
| Friday Night | 35°F | Mostly Cloudy | 0 to 5 mph N | 1% |
| Saturday | 53°F | Mostly Sunny | 2 mph NW | 2% |
| Saturday Night | 34°F | Mostly Clear | 2 mph WNW | 1% |
| Sunday | 60°F | Sunny | 2 to 6 mph WNW | 10% |
| Sunday Night | 35°F | Mostly Clear | 3 mph WNW | 3% |
| Monday | 64°F | Sunny | 1 to 8 mph W | 1% |
| Monday Night | 40°F | Mostly Clear | 5 mph WSW | 0% |
Forecast source: National Weather Service (api.weather.gov) for Marietta (40.499, -90.393). Updated through the day.
Growing snapshot for Marietta
Last spring frost
Apr 17
First fall frost
Oct 22
Growing season
185 days
Hardiness zone
6a
More local growing data for Marietta: nearby ZIP 61459 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Astoria
Avon
Bryant
Canton
Cuba
Dunfermline
Ellisville
Fairview
Farmington
Goofy Ridge
Ipava
Lewistown
Liverpool
London Mills
Norris
Smithfield
St. David
Table Grove
Vermont
Climate data from the nearest NOAA station, Prairie City 2S, Il (6.1 mi from Marietta). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.