weatherbycounty

Henry County Climate

JanFebMarAprMayJunJulAugSepOctNovDec49.6°AVG °F

Avg Annual Temp

49.6°F

Annual Precip

38.8"

Annual Snowfall

25.3"

Extreme Heat Days

20

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.4"
1.7"
2.3"
4.0"
5.1"
5.3"
4.3"
3.9"
4.0"
3.0"
2.1"
1.8"
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

3,118

Supports most vegetables & fruits

Last spring frost (32°F): 04/30
First fall frost (32°F): 10/10

Seasonal Overview

Comfort ZoneSpring38°61°11.4"Summer70°74°13.4"Fall39°65°9.1"Winter22°28°4.9"20°40°60°80°100°

National Comparison

Warmer than 29% of US counties
Wetter than 43% of US counties
More seasonal variation than 85% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Henry County

Climate Verdict

Henry County has a cool, averaging 49.6°F annually, moderate rainfall of 38.8 inches per year, rare extreme heat with only 19.9 days above 90°F annually, moderate snowfall of 25.3 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 22.0°F. summers are warm — July averages 73.5°F. Residents experience a substantial 52°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

Henry County closely matches the Iowa statewide average temperature of 48.0°F, it is somewhat wetter than average for Iowa.

Climate Profile

About Henry County Weather

Mild Temperatures in Southeast Iowa

Henry County averages 49.6°F annually, making it one of the warmer spots in the Upper Midwest. While still cooler than the national median, its climate offers a milder profile than much of the surrounding region.

Leading the State in Warmth

At 49.6°F, Henry County stays well above the Iowa state average of 48.0°F. It is also wetter than average, receiving 38.8 inches of precipitation compared to the state benchmark of 36.1 inches.

Warmest Among Local Peers

Henry County is noticeably warmer than Iowa County to its north, which averages 48.2°F. It also sees less snow than its northern neighbors, recording only 25.3 inches annually.

Hot Summers and Manageable Winters

The county experiences 20 days per year above 90°F, with a summer average of 71.6°F. Winters are among the state's mildest, with a January average of 22.0°F and relatively low snowfall of 25.3 inches.

Plan for Humidity and Rain

High annual precipitation of 38.8 inches makes moisture control and basement waterproofing a priority for homeowners. While winter is milder than elsewhere in Iowa, reliable HVAC systems are needed to manage the 20 days of extreme summer heat.

Frequently Asked Questions

What is the average temperature in Henry County?
The average annual temperature in Henry County, IA is 49.6°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Henry County get?
Henry County receives an average of 38.8 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 Henry County?
Yes, Henry County receives an average of 25.3 inches of snowfall per year according to NOAA climate normals.
How hot does Henry County get in summer?
The average summer temperature (June-August) in Henry County is 71.6°F. The county experiences an average of 20 days per year above 90°F.
How cold are winters in Henry County?
The average winter temperature (December-February) in Henry County is 25.4°F. January, typically the coldest month, averages 22.0°F.

Track your own weather in Henry 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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