Sumner, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sumner, a city in Bremer County, Iowa.
Overnight
64°F
Mostly Cloudy
Mostly cloudy, with a low around 64. South wind around 8 mph.
7-day forecast for Sumner
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 64°F | Mostly Cloudy | 8 mph S | 3% |
| Tuesday | 75°F | Chance Showers And Thunderstorms | 8 mph W | 48% |
| Tuesday Night | 60°F | Showers And Thunderstorms Likely | 5 to 8 mph NNW | 59% |
| Wednesday | 72°F | Slight Chance Showers And Thunderstorms then Partly Sunny | 5 mph N | 23% |
| Wednesday Night | 54°F | Mostly Clear | 3 mph N | 11% |
| Thursday | 77°F | Sunny | 3 mph ESE | 1% |
| Thursday Night | 59°F | Mostly Clear | 3 mph SSE | 0% |
| Friday | 80°F | Sunny | 3 to 12 mph S | 5% |
| Friday Night | 64°F | Mostly Clear | 8 mph S | 11% |
| Saturday | 82°F | Mostly Sunny | 6 to 10 mph SSW | 10% |
| Saturday Night | 68°F | Chance Rain Showers | 8 to 13 mph S | 30% |
| Sunday | 84°F | Chance Showers And Thunderstorms | 12 mph SSW | 30% |
| Sunday Night | 67°F | Slight Chance Showers And Thunderstorms | 9 mph S | 38% |
| Monday | 82°F | Chance Showers And Thunderstorms | 9 to 13 mph SSE | 38% |
Forecast source: National Weather Service (api.weather.gov) for Sumner (42.849, -92.097). Updated through the day.
Growing snapshot for Sumner
Last spring frost
Apr 29
First fall frost
Oct 9
Growing season
162 days
Hardiness zone
5a
More local growing data for Sumner: nearby ZIP 50674 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Tripoli, Ia (7.4 mi from Sumner). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.