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Polk County Climate

JanFebMarAprMayJunJulAugSepOctNovDec50.2°AVG °F

Avg Annual Temp

50.2°F

Annual Precip

36.6"

Annual Snowfall

33.1"

Extreme Heat Days

21

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.0"
1.2"
2.1"
4.0"
5.1"
5.3"
4.1"
4.3"
3.4"
2.7"
1.9"
1.5"
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

3,366

Supports most vegetables & fruits

Last spring frost (32°F): 04/19
First fall frost (32°F): 10/18

Seasonal Overview

Comfort ZoneSpring39°62°11.2"Summer72°75°13.7"Fall39°66°8.0"Winter21°27°3.7"20°40°60°80°100°

National Comparison

Warmer than 31% of US counties
Wetter than 37% of US counties
More seasonal variation than 90% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Polk County

Climate Verdict

Polk County has a mild, with an average annual temperature of 50.2°F, moderate rainfall of 36.6 inches per year, occasional hot days — 20.833333333333332 per year above 90°F, moderate snowfall of 33.1 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 21.5°F. summers are warm — July averages 75.5°F. Residents experience a substantial 54°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

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

Climate Profile

About Polk County Weather

A Balanced Mid-Continent Climate Profile

Polk County closely mirrors the national temperature median with an annual average of 50.2°F. Its 36.6 inches of precipitation are typical for the humid continental climate of the American Midwest.

Warmer and Wetter Than Iowa Norms

Polk County is 2.2 degrees warmer than the state average of 48.0°F. It also receives slightly more precipitation than the statewide mean, recording 36.6 inches annually.

A Warm Hub in Central Iowa

Compared to Poweshiek County to the east, Polk is significantly warmer, averaging 50.2°F versus 47.5°F. It also experiences 10 more days of extreme heat annually than its eastern neighbor.

Hot Summers and Steady Snowfall

July averages a warm 75.5°F, contributing to 21 days of extreme heat per year. Winter brings a consistent 33.1 inches of snow and a January average of 21.5°F.

Plan for High Summer Energy Demands

Residents should expect high cooling costs during the 21 days of 90°F+ weather. All-season tires and standard snow tools are sufficient for the 33.1 inches of winter snowfall.

Frequently Asked Questions

What is the average temperature in Polk County?
The average annual temperature in Polk County, IA is 50.2°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Polk County get?
Polk County receives an average of 36.6 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 Polk County?
Yes, Polk County receives an average of 33.1 inches of snowfall per year according to NOAA climate normals.
How hot does Polk County get in summer?
The average summer temperature (June-August) in Polk County is 73.5°F. The county experiences an average of 21 days per year above 90°F.
How cold are winters in Polk County?
The average winter temperature (December-February) in Polk County is 24.9°F. January, typically the coldest month, averages 21.5°F.

Track your own weather in Polk 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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