weatherbycounty

Harrison County Climate

JanFebMarAprMayJunJulAugSepOctNovDec48.6°AVG °F

Avg Annual Temp

48.6°F

Annual Precip

37.1"

Annual Snowfall

37.1"

Extreme Heat Days

25

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.8"
1.1"
2.0"
3.6"
5.0"
5.5"
4.5"
4.4"
4.3"
2.8"
1.6"
1.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5b

Minimum winter temperature range for plant survival

Growing Degree Days

3,139

Supports most vegetables & fruits

Last spring frost (32°F): 05/01
First fall frost (32°F): 10/08

Seasonal Overview

Comfort ZoneSpring37°61°10.7"Summer71°74°14.3"Fall36°64°8.7"Winter20°25°3.4"20°40°60°80°100°

National Comparison

Warmer than 26% of US counties
Wetter than 38% of US counties
More seasonal variation than 92% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Harrison County

Climate Verdict

Harrison County has a cool, averaging 48.6°F annually, moderate rainfall of 37.1 inches per year, occasional hot days — 24.95 per year above 90°F, moderate snowfall of 37.1 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 19.7°F. summers are warm — July averages 74.3°F. Residents experience a substantial 55°F difference between winter and summer.

Outdoor & Gardening Guidance

Growing season and gardening data is currently limited for Harrison County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.

Regional Context

Harrison County closely matches the Iowa statewide average temperature of 48.0°F.

Climate Profile

About Harrison County Weather

Western Iowa’s Warm and Wet Climate

Harrison County averages 48.6°F annually, keeping it warmer than many of its northern peers but still below the national median. Its humid continental climate is characterized by significant precipitation, totaling 37.1 inches per year.

Above the Iowa Temperature Baseline

Harrison is warmer and wetter than the average Iowa county, exceeding the state’s 48.0°F temperature and 36.1-inch precipitation marks. This makes it one of the more productive but humid agricultural zones in the region.

Hotter Than Central Neighbors

Compared to Ida County at 47.1°F, Harrison is significantly warmer and faces nearly double the number of extreme heat days. Its 25 days above 90°F set it apart from the cooler counties found further east and north.

Intense Summer Heat and Heavy Snow

July brings a warm average of 74.3°F and 25 days of extreme heat reaching at least 90°F. Despite the summer warmth, winters remain snowy with 37.1 inches of annual snowfall and a January average of 19.7°F.

Engineered for Extreme Peaks

Robust cooling systems are essential here given the high frequency of 90°F days. Residents must also maintain heavy-duty snow equipment to manage the 37.1 inches of annual accumulation that arrives during the winter months.

Frequently Asked Questions

What is the average temperature in Harrison County?
The average annual temperature in Harrison County, IA is 48.6°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Harrison County get?
Harrison County receives an average of 37.1 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Harrison County?
Yes, Harrison County receives an average of 37.1 inches of snowfall per year according to NOAA climate normals.
How hot does Harrison County get in summer?
The average summer temperature (June-August) in Harrison County is 72.5°F. The county experiences an average of 25 days per year above 90°F.
How cold are winters in Harrison County?
The average winter temperature (December-February) in Harrison County is 22.7°F. January, typically the coldest month, averages 19.7°F.

Track your own weather in Harrison County

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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