Ontario, IN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Ontario, a community in Lagrange County, Indiana.
Today
73°F
Showers And Thunderstorms Likely then Showers And Thunderstorms
Showers and thunderstorms likely before 10am, then showers and thunderstorms between 10am and 2pm, then a chance of showers and thunderstorms. Cloudy, with a high near 73. Southeast wind 5 to 10 mph. Chance of precipitation is 90%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast for Ontario
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 73°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 to 10 mph SE | 94% |
| Tonight | 63°F | Showers And Thunderstorms Likely | 5 mph S | 86% |
| Sunday | 71°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 to 15 mph N | 80% |
| Sunday Night | 51°F | Chance Rain Showers | 10 mph NE | 40% |
| Monday | 64°F | Slight Chance Rain Showers | 10 to 15 mph NE | 22% |
| Monday Night | 48°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 16% |
| Tuesday | 64°F | Partly Sunny then Slight Chance Rain Showers | 10 to 15 mph NE | 16% |
| Tuesday Night | 50°F | Chance Rain Showers | 10 to 15 mph NE | 39% |
| Wednesday | 64°F | Chance Rain Showers | 10 to 15 mph NE | 43% |
| Wednesday Night | 50°F | Chance Showers And Thunderstorms then Mostly Cloudy | 5 to 10 mph NE | 35% |
| Thursday | 67°F | Mostly Cloudy | 5 to 10 mph NE | 6% |
| Thursday Night | 50°F | Mostly Cloudy | 5 to 10 mph NE | 6% |
| Friday | 70°F | Mostly Sunny | 5 to 10 mph NE | 4% |
| Friday Night | 49°F | Partly Cloudy | 5 mph NE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Ontario (41.699, -85.385). Updated through the day.
Growing snapshot for Ontario
Last spring frost
Apr 26
First fall frost
Oct 21
Growing season
176 days
Hardiness zone
6a
More local growing data for Ontario: nearby ZIP 46746 weather · frost dates · planting calendar · Indiana frost dates
Nearby towns & communities
Adams Lake
Cree Lake
Howe
Lagrange
Mongo
Otter Lake
Scott
Shipshewana
Shipshewana Lake
South Milford
Stroh
Topeka
Wildwood
Climate data from the nearest NOAA station, Lagrange, In (6.4 mi from Ontario). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.