Harper, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Harper, a city in Keokuk County, Iowa.
Overnight
49°F
Slight Chance Rain Showers
A slight chance of rain showers after 5am. Cloudy. Low around 49, with temperatures rising to around 51 overnight. West wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 20%.
7-day forecast for Harper
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 49°F | Slight Chance Rain Showers | 15 mph W | 15% |
| Wednesday | 52°F | Slight Chance Rain Showers then Mostly Cloudy | 15 to 20 mph W | 20% |
| Wednesday Night | 44°F | Mostly Cloudy | 15 mph W | 10% |
| Thursday | 54°F | Rain Showers Likely | 10 to 15 mph W | 64% |
| Thursday Night | 41°F | Mostly Cloudy | 10 mph N | 13% |
| Friday | 49°F | Mostly Sunny | 5 to 10 mph N | 1% |
| Friday Night | 30°F | Partly Cloudy | 0 to 5 mph N | 0% |
| Saturday | 51°F | Mostly Sunny | 0 to 5 mph NW | 0% |
| Saturday Night | 34°F | Mostly Clear | 5 mph W | 1% |
| Sunday | 57°F | Sunny | 5 mph W | 1% |
| Sunday Night | 36°F | Clear | 5 mph SW | 0% |
| Monday | 63°F | Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 40°F | Mostly Clear | 5 mph W | 0% |
| Tuesday | 63°F | Sunny | 5 mph NW | 0% |
Forecast source: National Weather Service (api.weather.gov) for Harper (41.364, -92.051). Updated through the day.
Growing snapshot for Harper
Last spring frost
Apr 24
First fall frost
Oct 15
Growing season
172 days
Hardiness zone
5b
More local growing data for Harper: nearby ZIP 52231 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Delta
Gibson
Hayesville
Hedrick
Keswick
Kinross
Martinsburg
Ollie
Richland
Sigourney
South English
Thornburg
Webster
What Cheer
Climate data from the nearest NOAA station, Sigourney, Ia (8.9 mi from Harper). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.