Marathon, IA Weather & Growing Conditions
Tonight
40°F
Rain Showers
Rain showers. Cloudy. Low around 40, with temperatures rising to around 43 overnight. Northwest wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 40°F | Rain Showers | 15 mph NW | 84% |
| Wednesday | 48°F | Chance Rain Showers | 15 mph WNW | 40% |
| Wednesday Night | 39°F | Chance Rain Showers | 10 to 15 mph WNW | 46% |
| Thursday | 48°F | Mostly Cloudy | 10 to 15 mph NNW | 12% |
| Thursday Night | 33°F | Mostly Cloudy | 5 to 10 mph N | 2% |
| Friday | 47°F | Mostly Sunny | 0 to 5 mph NNE | 0% |
| Friday Night | 28°F | Partly Cloudy | 0 mph | 0% |
| Saturday | 50°F | Mostly Sunny | 0 to 5 mph SW | 0% |
| Saturday Night | 35°F | Mostly Clear | 5 mph W | 6% |
| Sunday | 59°F | Sunny | 5 mph WSW | 5% |
| Sunday Night | 37°F | Mostly Clear | 5 mph SSW | 1% |
| Monday | 62°F | Sunny | 5 to 10 mph WSW | 0% |
| Monday Night | 38°F | Mostly Clear | 5 mph WNW | 0% |
| Tuesday | 59°F | Mostly Sunny | 5 mph W | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Marathon, IA
Last spring frost
Apr 30
First fall frost
Oct 5
Growing season
159 days
Hardiness zone
5a
Explore more for Marathon, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Sioux Rapids 4 E, Ia (4.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.