Sumner, IA Weather & Growing Conditions
Today
75°F
Patchy Fog
Patchy fog and showers and thunderstorms likely before 1pm, then a chance of showers and thunderstorms between 1pm and 3pm, then showers and thunderstorms likely between 3pm and 5pm, then a chance of showers and thunderstorms. Mostly cloudy. High near 75, with temperatures falling to around 73 in the afternoon. Southwest wind around 9 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 75°F | Patchy Fog | 9 mph SW | 64% |
| Tonight | 58°F | Chance Showers And Thunderstorms | 10 to 14 mph N | 43% |
| Sunday | 66°F | Chance Rain Showers then Mostly Cloudy | 15 to 18 mph NE | 32% |
| Sunday Night | 52°F | Chance Rain Showers | 16 mph ENE | 34% |
| Monday | 61°F | Chance Rain Showers | 16 mph ENE | 34% |
| Monday Night | 47°F | Chance Rain Showers | 9 to 14 mph NE | 32% |
| Tuesday | 60°F | Slight Chance Rain Showers then Mostly Sunny | 9 to 13 mph ENE | 15% |
| Tuesday Night | 43°F | Mostly Clear | 7 mph ENE | 2% |
| Wednesday | 64°F | Sunny | 8 mph ENE | 1% |
| Wednesday Night | 48°F | Mostly Clear | 5 mph E | 3% |
| Thursday | 66°F | Mostly Sunny | 6 mph E | 7% |
| Thursday Night | 51°F | Partly Cloudy | 3 mph E | 4% |
| Friday | 68°F | Mostly Sunny | 3 to 7 mph ESE | 4% |
| Friday Night | 52°F | Partly Cloudy | 5 mph ESE | 7% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Sumner, IA
Last spring frost
Apr 29
First fall frost
Oct 9
Growing season
162 days
Hardiness zone
5a
Explore more for Sumner, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Tripoli, Ia (7.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.