weatherbycounty

Linn County Climate

JanFebMarAprMayJunJulAugSepOctNovDec48.2°AVG °F

Avg Annual Temp

48.2°F

Annual Precip

37.1"

Annual Snowfall

30.8"

Extreme Heat Days

14

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.1"
1.2"
1.9"
3.8"
4.5"
5.6"
4.6"
4.2"
3.7"
3.0"
2.1"
1.5"
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

2,966

Supports most vegetables & fruits

Last spring frost (32°F): 04/28
First fall frost (32°F): 10/11

Seasonal Overview

Comfort ZoneSpring36°60°10.2"Summer70°73°14.4"Fall37°63°8.7"Winter20°25°3.8"20°40°60°80°100°

National Comparison

Warmer than 24% of US counties
Wetter than 38% of US counties
More seasonal variation than 90% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Linn County

Climate Verdict

Linn County has a cool, averaging 48.2°F annually, moderate rainfall of 37.1 inches per year, rare extreme heat with only 13.566666666666665 days above 90°F annually, moderate snowfall of 30.8 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 19.5°F. summers are warm — July averages 73.0°F. Residents experience a substantial 53°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

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

Climate Profile

About Linn County Weather

Cooler than the national average

Linn County averages an annual temperature of 48.2°F, which is notably cooler than the national median. This humid continental climate features wide temperature swings between winter lows and summer highs.

Warmer than the Iowa average

At 48.2°F, Linn County sits just above the Iowa state average of 48.0°F. This makes it a mid-range county in terms of warmth compared to its 98 peers across the state.

A wetter climate than nearby neighbors

Linn receives 37.1 inches of annual precipitation, which is more than the state average of 36.1 inches. It experiences higher moisture levels than Marshall County to the west, which averages 35.9 inches.

Snowy winters and moderate heat

Winter temperatures average 22.9°F with 30.8 inches of annual snowfall. The summer months see 14 days where temperatures exceed 90°F, centering around a July average of 73.0°F.

Prepare for significant winter maintenance

Residents need high-capacity heating systems to manage January averages of 19.5°F. With over 30 inches of snow per year, reliable snow removal equipment is a household necessity.

Frequently Asked Questions

What is the average temperature in Linn County?
The average annual temperature in Linn County, IA is 48.2°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Linn County get?
Linn 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 Linn County?
Yes, Linn County receives an average of 30.8 inches of snowfall per year according to NOAA climate normals.
How hot does Linn County get in summer?
The average summer temperature (June-August) in Linn County is 71.2°F. The county experiences an average of 14 days per year above 90°F.
How cold are winters in Linn County?
The average winter temperature (December-February) in Linn County is 22.9°F. January, typically the coldest month, averages 19.5°F.

Track your own weather in Linn County

Ambient Weather personal weather stations give you hyperlocal climate data.

Shop Weather Stations →

Sponsored

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
← Back to Iowa