Marengo, IA Weather & Growing Conditions
This Afternoon
78°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Partly sunny, with a high near 78. Southwest wind around 5 mph. Chance of precipitation is 50%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 78°F | Chance Showers And Thunderstorms | 5 mph SW | 54% |
| Tonight | 61°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 5 mph N | 75% |
| Sunday | 66°F | Chance Rain Showers | 10 to 15 mph NE | 52% |
| Sunday Night | 55°F | Chance Rain Showers | 10 to 15 mph NE | 52% |
| Monday | 61°F | Rain Showers Likely | 10 to 15 mph NE | 74% |
| Monday Night | 50°F | Rain Showers Likely | 10 mph NE | 74% |
| Tuesday | 60°F | Chance Rain Showers | 10 mph NE | 30% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 10 mph NE | 7% |
| Wednesday | 63°F | Mostly Sunny | 5 mph NE | 2% |
| Wednesday Night | 51°F | Partly Cloudy | 0 to 5 mph E | 1% |
| Thursday | 66°F | Partly Sunny | 0 to 5 mph E | 14% |
| Thursday Night | 55°F | Slight Chance Rain Showers | 0 mph | 22% |
| Friday | 69°F | Slight Chance Rain Showers | 0 to 5 mph E | 19% |
| Friday Night | 56°F | Mostly Cloudy | 0 to 5 mph E | 12% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Marengo, IA
Last spring frost
Apr 28
First fall frost
Oct 9
Growing season
164 days
Hardiness zone
5a
Explore more for Marengo, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Williamsburg 1E, Ia (9.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.