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Arapahoe County Climate

Arapahoe County, Colorado

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec50.8°AVG °F

Avg Annual Temp

50.8°F

Annual Precip

Annual Snowfall

Extreme Heat Days

47

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Growing Season & Gardening

USDA Hardiness Zone

6a

Minimum winter temperature range for plant survival

Growing Degree Days

2,800

Supports most vegetables & fruits

Last spring frost (32°F): 05/07
First fall frost (32°F): 10/08

Seasonal Overview

Comfort ZoneSpring41°57°0.0"Summer67°73°0.0"Fall40°64°0.0"Winter32°34°0.0"20°40°60°80°100°

National Comparison

Warmer than 34% of US counties
More seasonal variation than 42% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Arapahoe County

Climate Verdict

Arapahoe County has a mild, with an average annual temperature of 50.8°F, occasional hot days — 46.6 per year above 90°F. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 32.1°F. summers are warm — July averages 73.4°F. The 41°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Arapahoe County is 4.9°F warmer than the Colorado statewide average of 45.9°F, the county experiences 19.983965734441934 more extreme heat days than the state average.

Climate Profile

About Arapahoe County Weather

Arapahoe: Urban heat on the plains

Arapahoe County averages 50.8°F annually, running 4.8 degrees warmer than the U.S. median of 46°F. The county's semi-arid climate and Denver metro location create a warm, dry environment, though detailed precipitation records are limited.

Colorado's warmest tier

At 50.8°F, Arapahoe ranks among Colorado's warmest counties, sitting 4.8 degrees above the state average of 46°F. This reflects its Front Range elevation and the urban heat-island effect from the Denver metropolitan area.

Metro core shapes temperature

Arapahoe (50.8°F) nearly matches adjacent Adams County (50.7°F) and runs significantly warmer than surrounding mountain counties like Boulder (44°F). The metro sprawl creates a distinct warm corridor across the northern Front Range.

Hot summers, quick winters

Summer temperatures average 70.6°F while winters drop to 32.7°F, with 47 days per year reaching 90°F or higher. January averages 32.1°F, and while annual snowfall data is limited, winter precipitation is moderate by plains standards.

Cool homes, lighter winter prep

With 47 annual extreme heat days, air conditioning is essential and high-efficiency systems save significantly on summer costs. Winter demands solid heating but is less severe than mountain counties; water-efficient landscaping suits the dry climate.

Frequently Asked Questions

What is the average temperature in Arapahoe County?
The average annual temperature in Arapahoe County, CO is 50.8°F, based on NOAA 30-year climate normals (1991-2020).
How hot does Arapahoe County get in summer?
The average summer temperature (June-August) in Arapahoe County is 70.6°F. The county experiences an average of 47 days per year above 90°F.
How cold are winters in Arapahoe County?
The average winter temperature (December-February) in Arapahoe County is 32.7°F. January, typically the coldest month, averages 32.1°F.

Track your own weather in Arapahoe 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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