Marengo, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Marengo, a city in Iowa County, Iowa.
Today
84°F
Partly Sunny then Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 1pm. Partly sunny. High near 84, with temperatures falling to around 81 in the afternoon. West wind 5 to 10 mph. Chance of precipitation is 40%.
7-day forecast for Marengo
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Partly Sunny then Chance Showers And Thunderstorms | 5 to 10 mph W | 37% |
| Tonight | 63°F | Showers And Thunderstorms Likely | 5 to 10 mph N | 84% |
| Wednesday | 76°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 5 mph N | 74% |
| Wednesday Night | 56°F | Chance Showers And Thunderstorms | 0 to 5 mph N | 37% |
| Thursday | 81°F | Sunny | 0 to 5 mph NE | 12% |
| Thursday Night | 59°F | Mostly Clear | 0 mph | 1% |
| Friday | 84°F | Sunny | 0 to 5 mph SE | 5% |
| Friday Night | 64°F | Mostly Clear | 5 mph S | 13% |
| Saturday | 88°F | Sunny | 5 mph S | 10% |
| Saturday Night | 70°F | Mostly Clear then Slight Chance Showers And Thunderstorms | 5 to 10 mph S | 15% |
| Sunday | 89°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 10 mph S | 15% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 5 to 10 mph S | 37% |
| Monday | 88°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 10 mph S | 37% |
| Monday Night | 69°F | Slight Chance Showers And Thunderstorms | 10 mph E | 32% |
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 Aug 4, 2026.