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Oswego, IN Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Oswego, a community in Kosciusko County, Indiana.

Tonight
57°F
Mostly Cloudy then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 5am. Mostly cloudy. Low around 57, with temperatures rising to around 62 overnight. East wind 5 to 10 mph. Chance of precipitation is 20%.

7-day forecast for Oswego

WhenTempForecastWindPrecip
Tonight 57°F Mostly Cloudy then Slight Chance Showers And Thunderstorms 5 to 10 mph E 18%
Saturday 77°F Showers And Thunderstorms 5 to 10 mph SE 79%
Saturday Night 64°F Chance Showers And Thunderstorms then Showers And Thunderstorms 5 mph S 80%
Sunday 74°F Showers And Thunderstorms 5 to 10 mph NW 77%
Sunday Night 53°F Rain Showers Likely 10 mph NE 56%
Monday 66°F Chance Showers And Thunderstorms 10 to 15 mph NE 52%
Monday Night 50°F Chance Rain Showers 10 to 15 mph NE 34%
Tuesday 66°F Slight Chance Rain Showers 10 to 15 mph NE 21%
Tuesday Night 51°F Slight Chance Rain Showers 5 to 10 mph NE 21%
Wednesday 66°F Slight Chance Rain Showers then Mostly Cloudy 10 mph NE 16%
Wednesday Night 51°F Mostly Cloudy 5 to 10 mph NE 12%
Thursday 69°F Partly Sunny 5 to 10 mph N 6%
Thursday Night 51°F Mostly Cloudy 0 to 10 mph NE 6%
Friday 71°F Mostly Sunny 0 to 5 mph N 5%

Forecast source: National Weather Service (api.weather.gov) for Oswego (41.322, -85.787). Updated through the day.

Growing snapshot for Oswego

Last spring frost
Apr 28
First fall frost
Oct 18
Growing season
170 days
Hardiness zone
6a

More local growing data for Oswego: nearby ZIP 46538 weather · frost dates · planting calendar · Indiana frost dates

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Climate data from the nearest NOAA station, Warsaw, In (5.2 mi from Oswego). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.