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Summit County Climate

JanFebMarAprMayJunJulAugSepOctNovDec37.0°AVG °F

Avg Annual Temp

37.0°F

Annual Precip

17.7"

Annual Snowfall

150.1"

Extreme Heat Days

0

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
1.3"
1.3"
1.5"
1.9"
1.7"
1.1"
2.0"
1.9"
1.5"
1.2"
1.1"
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

758

Limited to cold-tolerant varieties

Last spring frost (32°F): -9999.0
First fall frost (32°F): -9999.0

Seasonal Overview

Comfort ZoneSpring27°44°5.1"Summer54°59°5.0"Fall27°50°3.8"Winter16°19°3.8"20°40°60°80°100°

National Comparison

Warmer than 1% of US counties
Wetter than 11% of US counties
More seasonal variation than 51% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Summit County

Climate Verdict

Summit County has a cold, with an average annual temperature of 37.0°F, semi-arid conditions with only 17.7 inches of annual precipitation, rare extreme heat with only 0.35 days above 90°F annually, heavy winter snowfall averaging 150.1 inches per year. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 16.0°F. summers are cool, with July averaging only 59.1°F. The 43°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

Winter sports enthusiasts benefit from reliable snow cover for 3-4 months annually.

Regional Context

Summit County is 8.8°F cooler than the Colorado statewide average of 45.9°F, the county experiences 26.266034265558066 fewer extreme heat days than the state average.

Climate Profile

About Summit County Weather

Summit's alpine climate stands apart nationally

Summit County's 37.0°F annual average is nearly 10°F colder than the U.S. median of 47°F, placing it firmly in a subalpine climate zone. Despite only 17.7 inches of annual precipitation, the county's extreme elevation means nearly all moisture falls as snow, not rain.

Colorado's coldest inhabited county

Summit ranks as one of Colorado's coldest counties, at 37.0°F—a full 9°F below the state average of 46.0°F. This dramatic temperature difference reflects Summit's high elevation (average above 9,000 feet) and mountain geography.

Significantly colder than Teller County peaks

Summit's 37.0°F average is 4°F colder than nearby Teller County (41.0°F), despite both being mountain regions, because Summit sits at higher elevations. This temperature gap expands seasonally: Summit's summer only reaches 56.6°F compared to Teller's 59.0°F.

Extreme winter dominance with no summer heat

Summit records zero days above 90°F annually, while January plunges to 16.0°F and July peaks at just 59.1°F. The county receives a remarkable 150.1 inches of snow per year—more than 12 feet—making winter the defining season.

Prepare for brutal snow, never for heat

Summit residents must invest in robust snow removal equipment and avalanche mitigation, as 150+ inches annually can paralyze transportation. Heavy-duty insulation, backup heating systems, and tire chains are year-round necessities; air conditioning is virtually never required.

Frequently Asked Questions

What is the average temperature in Summit County?
The average annual temperature in Summit County, CO is 37.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Summit County get?
Summit County receives an average of 17.7 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 Summit County?
Yes, Summit County receives an average of 150.1 inches of snowfall per year according to NOAA climate normals.
How hot does Summit County get in summer?
The average summer temperature (June-August) in Summit County is 56.6°F. The county experiences an average of 0 days per year above 90°F.
How cold are winters in Summit County?
The average winter temperature (December-February) in Summit County is 17.5°F. January, typically the coldest month, averages 16.0°F.

Track your own weather in Summit 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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