Marathon, IA Weather & Growing Conditions
Today
71°F
Patchy Fog
Patchy fog and a slight chance of rain showers before 2pm. Cloudy. High near 71, with temperatures falling to around 68 in the afternoon. North wind 5 to 10 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 71°F | Patchy Fog | 5 to 10 mph N | 23% |
| Tonight | 57°F | Slight Chance Rain Showers then Cloudy | 10 mph NNE | 17% |
| Sunday | 66°F | Cloudy then Slight Chance Rain Showers | 10 to 15 mph NE | 18% |
| Sunday Night | 52°F | Rain Showers Likely | 10 mph ENE | 56% |
| Monday | 60°F | Rain Showers Likely | 10 mph ENE | 56% |
| Monday Night | 47°F | Chance Rain Showers then Mostly Cloudy | 5 mph ENE | 40% |
| Tuesday | 61°F | Mostly Sunny | 5 mph E | 10% |
| Tuesday Night | 43°F | Partly Cloudy | 0 to 5 mph ESE | 1% |
| Wednesday | 65°F | Mostly Sunny | 0 to 5 mph SE | 2% |
| Wednesday Night | 48°F | Partly Cloudy then Slight Chance Rain Showers | 0 to 5 mph SE | 15% |
| Thursday | 67°F | Slight Chance Rain Showers | 0 to 5 mph SE | 18% |
| Thursday Night | 52°F | Mostly Cloudy | 0 to 5 mph SE | 13% |
| Friday | 70°F | Partly Sunny | 5 mph SE | 13% |
| Friday Night | 53°F | Mostly Cloudy | 5 mph SE | 14% |
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 Sep 19, 2026.