Marengo, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Marengo, a city in Iowa County, Iowa.
This Afternoon
81°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 1pm, then a chance of showers and thunderstorms. Mostly cloudy, with a high near 81. Southwest wind around 10 mph. Chance of precipitation is 50%.
7-day forecast for Marengo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 81°F | Chance Showers And Thunderstorms | 10 mph SW | 47% |
| Tonight | 62°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 10 mph NW | 71% |
| Sunday | 68°F | Showers And Thunderstorms Likely then Slight Chance Showers And Thunderstorms | 10 to 15 mph NE | 67% |
| Sunday Night | 55°F | Chance Rain Showers | 10 to 15 mph NE | 52% |
| Monday | 63°F | Chance Rain Showers | 10 to 15 mph NE | 52% |
| Monday Night | 50°F | Chance Rain Showers | 5 to 10 mph NE | 41% |
| Tuesday | 61°F | Chance Rain Showers then Partly Sunny | 10 mph NE | 28% |
| Tuesday Night | 45°F | Partly Cloudy | 5 mph NE | 4% |
| Wednesday | 66°F | Sunny | 5 mph NE | 0% |
| Wednesday Night | 50°F | Partly Cloudy | 0 to 5 mph NE | 2% |
| Thursday | 67°F | Partly Sunny | 0 to 5 mph E | 7% |
| Thursday Night | 53°F | Partly Cloudy | 0 to 5 mph E | 5% |
| Friday | 70°F | Mostly Sunny | 0 to 5 mph E | 6% |
| Friday Night | 53°F | Partly Cloudy | 0 to 5 mph E | 8% |
Forecast source: National Weather Service (api.weather.gov) for Marengo (41.796, -92.068). Updated through the day.
Growing snapshot for Marengo
Last spring frost
Apr 28
First fall frost
Oct 9
Growing season
164 days
Hardiness zone
5a
More local growing data for Marengo: nearby ZIP 52301 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Amana
Conroy
East Amana
High Amana
Homestead
Ladora
Middle Amana
Millersburg
North English
Parnell
South Amana
Victor
West Amana
Williamsburg
Climate data from the nearest NOAA station, Williamsburg 1E, Ia (9.6 mi from Marengo). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.