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Clinton County Climate

JanFebMarAprMayJunJulAugSepOctNovDec50.2°AVG °F

Avg Annual Temp

50.2°F

Annual Precip

37.2"

Annual Snowfall

30.3"

Extreme Heat Days

15

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.4"
1.6"
2.4"
3.6"
4.5"
4.8"
4.0"
4.3"
3.7"
2.7"
2.2"
1.8"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

5a

Minimum winter temperature range for plant survival

Growing Degree Days

3,282

Supports most vegetables & fruits

Last spring frost (32°F): 04/22
First fall frost (32°F): 10/16

Seasonal Overview

Comfort ZoneSpring39°62°10.5"Summer71°74°13.2"Fall39°65°8.7"Winter22°28°4.8"20°40°60°80°100°

National Comparison

Warmer than 31% of US counties
Wetter than 39% of US counties
More seasonal variation than 87% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Clinton County

Climate Verdict

Clinton County has a mild, with an average annual temperature of 50.2°F, moderate rainfall of 37.2 inches per year, rare extreme heat with only 14.5 days above 90°F annually, moderate snowfall of 30.3 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 21.9°F. summers are warm — July averages 74.4°F. Residents experience a substantial 53°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

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

Climate Profile

About Clinton County Weather

Clinton County enjoys a warmer Iowa climate

At 50.2°F, Clinton County's average temperature is one of the highest in the state, though still below the national median. This eastern county experiences the full range of humid continental seasons with a milder edge.

One of the state's warmest regions

Clinton County's average annual temperature of 50.2°F is 2.2 degrees higher than the state average. It also receives 37.2 inches of precipitation, slightly more than the Iowa norm of 36.1 inches.

Less snow than the northern interior

The county receives 30.3 inches of snow, which is significantly less than the 40+ inches seen in counties like Clay. Its 15 extreme heat days represent a middle ground between the cooler north and hotter south.

Longer summers and milder winter lows

July averages 74.4°F, while the winter average of 25.2°F is the warmest among this group. This results in less extreme cold, though 15 days of 90°F heat still occur each year.

Prioritize humidity control and rain prep

With 37.2 inches of annual precipitation and warmer temperatures, humidity can be high; dehumidifiers are a smart home investment. Residents should still keep a snow shovel ready for the 30.3 inches of annual snowfall.

Frequently Asked Questions

What is the average temperature in Clinton County?
The average annual temperature in Clinton County, IA is 50.2°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Clinton County get?
Clinton County receives an average of 37.2 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 Clinton County?
Yes, Clinton County receives an average of 30.3 inches of snowfall per year according to NOAA climate normals.
How hot does Clinton County get in summer?
The average summer temperature (June-August) in Clinton County is 72.6°F. The county experiences an average of 15 days per year above 90°F.
How cold are winters in Clinton County?
The average winter temperature (December-February) in Clinton County is 25.2°F. January, typically the coldest month, averages 21.9°F.

Track your own weather in Clinton 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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