Harpers Ferry, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Harpers Ferry, a city in Allamakee County, Iowa.
Today
55°F
Chance Rain Showers
A chance of rain showers. Cloudy. High near 55, with temperatures falling to around 51 in the afternoon. Southwest wind around 14 mph, with gusts as high as 25 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Harpers Ferry
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 55°F | Chance Rain Showers | 14 mph SW | 36% |
| Tonight | 45°F | Rain Showers | 9 to 13 mph SW | 78% |
| Thursday | 50°F | Chance Rain Showers | 9 to 14 mph NW | 53% |
| Thursday Night | 37°F | Mostly Cloudy then Slight Chance Rain Showers | 3 to 8 mph N | 17% |
| Friday | 50°F | Mostly Sunny | 5 mph N | 0% |
| Friday Night | 29°F | Mostly Clear | 1 mph N | 0% |
| Saturday | 52°F | Sunny | 2 mph W | 0% |
| Saturday Night | 34°F | Mostly Clear | 1 mph W | 2% |
| Sunday | 58°F | Sunny | 1 to 5 mph W | 4% |
| Sunday Night | 35°F | Mostly Clear | 2 mph SW | 0% |
| Monday | 63°F | Sunny | 0 to 7 mph SW | 0% |
| Monday Night | 40°F | Mostly Clear | 0 to 3 mph W | 0% |
| Tuesday | 62°F | Sunny | 2 mph NW | 0% |
| Tuesday Night | 39°F | Partly Cloudy | 0 mph | 2% |
Forecast source: National Weather Service (api.weather.gov) for Harpers Ferry (43.201, -91.152). Updated through the day.
Growing snapshot for Harpers Ferry
Last spring frost
Apr 24
First fall frost
Oct 17
Growing season
175 days
Hardiness zone
5a
More local growing data for Harpers Ferry: nearby ZIP 52146 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Lynxville Dam 9, Wi (5.9 mi from Harpers Ferry). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.