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Tiffin, IA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Tiffin, a city in Johnson County, Iowa.

Overnight
50°F
Mostly Cloudy
Mostly cloudy. Low around 50, with temperatures rising to around 52 overnight. Southwest wind around 10 mph.

7-day forecast for Tiffin

WhenTempForecastWindPrecip
Overnight 50°F Mostly Cloudy 10 mph SW 14%
Wednesday 52°F Chance Rain Showers then Mostly Cloudy 15 mph W 29%
Wednesday Night 45°F Mostly Cloudy then Slight Chance Rain Showers 10 to 15 mph W 15%
Thursday 54°F Rain Showers Likely 10 to 15 mph NW 61%
Thursday Night 41°F Mostly Cloudy 5 to 10 mph N 11%
Friday 49°F Mostly Sunny 5 to 10 mph N 5%
Friday Night 31°F Mostly Clear 0 to 5 mph N 0%
Saturday 51°F Sunny 0 to 5 mph NW 0%
Saturday Night 35°F Mostly Clear 0 to 5 mph W 1%
Sunday 57°F Sunny 5 mph W 2%
Sunday Night 36°F Clear 0 to 5 mph SW 0%
Monday 62°F Sunny 5 to 10 mph SW 0%
Monday Night 41°F Mostly Clear 5 mph W 0%
Tuesday 62°F Sunny 5 mph NW 0%

Forecast source: National Weather Service (api.weather.gov) for Tiffin (41.705, -91.654). Updated through the day.

Growing snapshot for Tiffin

Last spring frost
Apr 21
First fall frost
Oct 18
Growing season
180 days
Hardiness zone
5b

More local growing data for Tiffin: nearby ZIP 52340 weather · frost dates · planting calendar · Iowa frost dates

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Climate data from the nearest NOAA station, Iowa City Muni Ap, Ia (8.5 mi from Tiffin). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.