weatherbycounty

Marshall County Climate

JanFebMarAprMayJunJulAugSepOctNovDec47.7°AVG °F

Avg Annual Temp

47.7°F

Annual Precip

35.9"

Annual Snowfall

26.5"

Extreme Heat Days

13

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.9"
0.9"
1.9"
3.8"
4.9"
5.6"
4.2"
4.3"
3.7"
2.6"
2.0"
1.2"
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

2,908

Supports most vegetables & fruits

Last spring frost (32°F): 04/30
First fall frost (32°F): 10/07

Seasonal Overview

Comfort ZoneSpring35°60°10.6"Summer70°73°14.1"Fall36°63°8.2"Winter19°24°3.1"20°40°60°80°100°

National Comparison

Warmer than 22% of US counties
Wetter than 36% of US counties
More seasonal variation than 91% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Marshall County

Climate Verdict

Marshall County has a cool, averaging 47.7°F annually, moderate rainfall of 35.9 inches per year, rare extreme heat with only 12.55 days above 90°F annually, moderate snowfall of 26.5 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 18.5°F. summers are warm — July averages 72.8°F. Residents experience a substantial 54°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

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

Climate Profile

About Marshall County Weather

Cooler and temperate year-round

Marshall County's 47.7°F average temperature is cooler than the national median. Its position in central Iowa results in a classic continental climate with no dry season.

Slightly cooler than the state

Marshall County sits just below the Iowa average temperature of 48.0°F. Its annual precipitation of 35.9 inches also falls just shy of the state average of 36.1 inches.

Fewer extreme heat days

With only 13 days above 90°F, Marshall is milder in the summer than neighbors like Linn or Marion. It is also drier than Linn County, receiving about 1.2 inches less rain each year.

Predictable snow and mild summers

The county receives 26.5 inches of snow annually, paired with a 22.0°F winter average. Summer is moderate, with a July average of 72.8°F and relatively few extreme heat days.

Stable climate with winter needs

The 26.5 inches of snow requires standard removal equipment, though it is less than some eastern neighbors. Efficient heating is necessary for the January average of 18.5°F.

Frequently Asked Questions

What is the average temperature in Marshall County?
The average annual temperature in Marshall County, IA is 47.7°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Marshall County get?
Marshall County receives an average of 35.9 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 Marshall County?
Yes, Marshall County receives an average of 26.5 inches of snowfall per year according to NOAA climate normals.
How hot does Marshall County get in summer?
The average summer temperature (June-August) in Marshall County is 71.0°F. The county experiences an average of 13 days per year above 90°F.
How cold are winters in Marshall County?
The average winter temperature (December-February) in Marshall County is 22.0°F. January, typically the coldest month, averages 18.5°F.

Track your own weather in Marshall 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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