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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.

This Afternoon
73°F
Showers And Thunderstorms
Showers and thunderstorms before 5pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 73. Southeast wind 5 to 10 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.

7-day forecast for Ontario

WhenTempForecastWindPrecip
This Afternoon 73°F Showers And Thunderstorms 5 to 10 mph SE 78%
Tonight 64°F Chance Showers And Thunderstorms then Showers And Thunderstorms 5 mph SE 86%
Sunday 71°F Showers And Thunderstorms 5 to 10 mph N 79%
Sunday Night 51°F Chance Rain Showers 10 mph NE 40%
Monday 65°F Chance Rain Showers 10 to 15 mph NE 27%
Monday Night 48°F Slight Chance Rain Showers then Mostly Cloudy 10 to 15 mph NE 18%
Tuesday 64°F Mostly Cloudy 10 to 15 mph NE 14%
Tuesday Night 51°F Mostly Cloudy then Chance Rain Showers 10 to 15 mph NE 40%
Wednesday 63°F Chance Rain Showers 10 to 15 mph NE 47%
Wednesday Night 51°F Chance Rain Showers then Mostly Cloudy 5 to 15 mph NE 46%
Thursday 67°F Partly Sunny 5 to 10 mph NE 9%
Thursday Night 51°F Mostly Cloudy 5 to 10 mph NE 9%
Friday 70°F Partly Sunny 5 mph NE 7%
Friday Night 50°F Partly Cloudy 0 to 5 mph NE 7%

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.