Seneca, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Seneca, a village in Lasalle County, Illinois.
Tonight
48°F
Areas Of Drizzle
Areas of drizzle. Cloudy, with a low around 48. Southwest wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 40%.
7-day forecast for Seneca
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 48°F | Areas Of Drizzle | 10 to 15 mph SW | 35% |
| Thursday | 53°F | Cloudy then Chance Rain Showers | 10 to 15 mph WSW | 40% |
| Thursday Night | 40°F | Chance Rain then Cloudy | 10 mph NNW | 33% |
| Friday | 50°F | Partly Sunny | 10 mph N | 3% |
| Friday Night | 32°F | Partly Cloudy | 0 to 5 mph NNW | 0% |
| Saturday | 51°F | Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 33°F | Mostly Clear | 0 mph | 0% |
| Sunday | 58°F | Sunny | 0 to 5 mph W | 1% |
| Sunday Night | 36°F | Mostly Clear | 0 to 5 mph W | 0% |
| Monday | 62°F | Sunny | 0 to 5 mph WSW | 0% |
| Monday Night | 40°F | Clear | 0 to 5 mph WSW | 0% |
| Tuesday | 63°F | Sunny | 0 to 5 mph WNW | 1% |
| Tuesday Night | 39°F | Partly Cloudy | 0 mph | 2% |
| Veterans Day | 62°F | Mostly Sunny | 0 to 5 mph NNW | 2% |
Forecast source: National Weather Service (api.weather.gov) for Seneca (41.303, -88.615). Updated through the day.
Growing snapshot for Seneca
Last spring frost
Apr 27
First fall frost
Oct 17
Growing season
171 days
Hardiness zone
5b
More local growing data for Seneca: nearby ZIP 61360 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Cedar Point
Dana
Dayton
Earlville
Grand Ridge
Harding
Kangley
LaSalle
Leland
Leonore
Lostant
Marseilles
Mendota
Millington
Naplate
Newark
North Utica
Oglesby
Ottawa
Peru
Ransom
Rutland
Serena
Sheridan
Streator
Tonica
Triumph
Troy Grove
Wedron
Wenona
Climate data from the nearest NOAA station, Marseilles Lock, Il (7.9 mi from Seneca). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 5, 2026.