Winthrop, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Winthrop, a city in Buchanan County, Iowa.
Today
51°F
Chance Rain Showers
A chance of rain showers. Cloudy, with a high near 51. West wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 50%.
7-day forecast for Winthrop
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 51°F | Chance Rain Showers | 15 mph W | 49% |
| Tonight | 44°F | Chance Rain Showers | 15 mph W | 44% |
| Thursday | 52°F | Chance Rain Showers | 10 to 15 mph NW | 38% |
| Thursday Night | 37°F | Mostly Cloudy | 10 mph N | 14% |
| Friday | 47°F | Mostly Sunny | 5 to 10 mph N | 1% |
| Friday Night | 29°F | Mostly Clear | 0 to 5 mph N | 0% |
| Saturday | 50°F | Sunny | 0 to 5 mph NW | 1% |
| Saturday Night | 34°F | Mostly Clear | 5 mph W | 1% |
| Sunday | 55°F | Sunny | 5 to 10 mph W | 3% |
| Sunday Night | 35°F | Clear | 5 mph SW | 0% |
| Monday | 60°F | Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 39°F | Mostly Clear | 5 mph W | 0% |
| Tuesday | 59°F | Sunny | 5 mph NW | 0% |
| Tuesday Night | 40°F | Partly Cloudy | 5 mph N | 1% |
Forecast source: National Weather Service (api.weather.gov) for Winthrop (42.471, -91.737). Updated through the day.
Growing snapshot for Winthrop
Last spring frost
Apr 30
First fall frost
Oct 7
Growing season
159 days
Hardiness zone
5a
More local growing data for Winthrop: nearby ZIP 50682 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Independence #1, Ia (10.8 mi from Winthrop). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.