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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

WhenTempForecastWindPrecip
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

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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.