Marengo, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Marengo, a city in Iowa County, Iowa.
This Afternoon
52°F
Slight Chance Drizzle
A slight chance of drizzle. Cloudy. High near 52, with temperatures falling to around 50 in the afternoon. West wind 10 to 15 mph, with gusts as high as 25 mph.
7-day forecast for Marengo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 52°F | Slight Chance Drizzle | 10 to 15 mph W | 11% |
| Tonight | 46°F | Slight Chance Rain Showers | 10 mph W | 19% |
| Thursday | 51°F | Chance Rain Showers | 10 mph NW | 36% |
| Thursday Night | 36°F | Mostly Cloudy | 5 to 10 mph N | 9% |
| Friday | 48°F | Mostly Sunny | 5 to 10 mph N | 0% |
| Friday Night | 27°F | Mostly Clear | 0 to 5 mph N | 0% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph W | 0% |
| Saturday Night | 32°F | Mostly Clear | 0 to 5 mph W | 0% |
| Sunday | 59°F | Sunny | 5 mph W | 0% |
| Sunday Night | 35°F | Clear | 0 to 5 mph SW | 0% |
| Monday | 65°F | Sunny | 0 to 10 mph SW | 0% |
| Monday Night | 39°F | Clear | 0 to 5 mph W | 0% |
| Tuesday | 62°F | Sunny | 0 to 5 mph NW | 2% |
| Tuesday Night | 39°F | Partly Cloudy | 0 mph | 1% |
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 Nov 5, 2026.