Tiffin, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Tiffin, a city in Johnson County, Iowa.
Tonight
63°F
Chance Showers And Thunderstorms then Showers And Thunderstorms Likely
A chance of rain showers before 10pm, then a chance of showers and thunderstorms between 10pm and 11pm, then showers and thunderstorms likely between 11pm and 1am, then showers and thunderstorms. Some of the storms could produce heavy rain. Mostly cloudy. Low around 63, with temperatures rising to around 66 overnight. North wind 5 to 10 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.
7-day forecast for Tiffin
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 63°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph N | 87% |
| Sunday | 66°F | Rain Showers Likely | 10 to 15 mph NE | 58% |
| Sunday Night | 57°F | Showers And Thunderstorms Likely | 10 to 15 mph NE | 55% |
| Monday | 61°F | Rain Showers Likely | 15 mph NE | 70% |
| Monday Night | 52°F | Rain Showers Likely | 10 mph NE | 64% |
| Tuesday | 60°F | Chance Rain Showers | 10 mph NE | 44% |
| Tuesday Night | 49°F | Partly Cloudy | 5 to 10 mph NE | 7% |
| Wednesday | 63°F | Mostly Sunny | 5 mph NE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 0 to 5 mph NE | 1% |
| Thursday | 66°F | Partly Sunny | 0 to 5 mph E | 9% |
| Thursday Night | 56°F | Slight Chance Rain Showers | 0 to 5 mph E | 20% |
| Friday | 69°F | Slight Chance Rain Showers | 0 to 5 mph E | 18% |
| Friday Night | 57°F | Partly Cloudy | 5 mph E | 12% |
| Saturday | 69°F | Partly Sunny | 5 mph E | 13% |
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
Nearby towns & communities
Coralville
Frytown
Hills
Iowa City
Kalona
Lone Tree
North Liberty
Oxford
Shueyville
Solon
Swisher
University Heights
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 Sep 20, 2026.