weatherbycounty

Lyon County Climate

JanFebMarAprMayJunJulAugSepOctNovDec46.0°AVG °F

Avg Annual Temp

46.0°F

Annual Precip

29.3"

Annual Snowfall

34.9"

Extreme Heat Days

19

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.6"
0.7"
1.5"
3.0"
4.0"
5.0"
3.6"
3.1"
3.2"
2.2"
1.4"
0.8"
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

2,824

Supports most vegetables & fruits

Last spring frost (32°F): 05/01
First fall frost (32°F): 10/04

Seasonal Overview

Comfort ZoneSpring33°59°8.5"Summer70°73°11.7"Fall34°62°6.9"Winter16°21°2.1"20°40°60°80°100°

National Comparison

Warmer than 16% of US counties
Wetter than 26% of US counties
More seasonal variation than 96% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Lyon County

Climate Verdict

Lyon County has a cool, averaging 46.0°F annually, moderate rainfall of 29.3 inches per year, rare extreme heat with only 18.5 days above 90°F annually, moderate snowfall of 34.9 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 15.6°F. summers are warm — July averages 73.3°F. Residents experience a substantial 58°F difference between winter and summer.

Outdoor & Gardening Guidance

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

Regional Context

Lyon County closely matches the Iowa statewide average temperature of 48.0°F, it is also noticeably drier, receiving 6.8 inches less precipitation than the state average.

Climate Profile

About Lyon County Weather

The cold edge of the prairie

Lyon County is one of the cooler spots in the nation with an annual average of just 46.0°F. This is significantly lower than the national median, reflecting its position in the far northwest corner of Iowa.

Colder and drier than the state

Lyon's 46.0°F average is 2.0 degrees lower than the Iowa state average. It is also considerably drier than the rest of the state, receiving only 29.3 inches of precipitation annually.

A unique climate among neighbors

Lyon is notably colder and drier than Marshall County, which averages 47.7°F and 35.9 inches of rain. Despite the cold, it surprisingly records 19 days of extreme heat, more than many warmer counties.

Harsh winters and high-contrast summers

Winter is intense here, with a January average of only 15.6°F and 34.9 inches of snow. Summers reach a July average of 73.3°F, creating a massive temperature swing between seasons.

Heavy-duty heating is mandatory

With a winter average of 19.1°F, residents must invest in high-performance HVAC systems. The combination of 34.9 inches of snow and extreme January lows requires specialized winter gear.

Frequently Asked Questions

What is the average temperature in Lyon County?
The average annual temperature in Lyon County, IA is 46.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Lyon County get?
Lyon County receives an average of 29.3 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 Lyon County?
Yes, Lyon County receives an average of 34.9 inches of snowfall per year according to NOAA climate normals.
How hot does Lyon County get in summer?
The average summer temperature (June-August) in Lyon County is 71.1°F. The county experiences an average of 19 days per year above 90°F.
How cold are winters in Lyon County?
The average winter temperature (December-February) in Lyon County is 19.1°F. January, typically the coldest month, averages 15.6°F.

Track your own weather in Lyon 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