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Alamosa County Climate

Alamosa County, Colorado

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec42.5°AVG °F

Avg Annual Temp

42.5°F

Annual Precip

8.7"

Annual Snowfall

34.5"

Extreme Heat Days

2

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
0.4"
0.3"
0.6"
0.7"
0.8"
0.5"
1.3"
1.5"
1.1"
0.7"
0.4"
0.4"
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

1,500

Favors cool-season crops

Last spring frost (32°F): 06/06
First fall frost (32°F): 09/17

Seasonal Overview

Comfort ZoneSpring35°51°2.1"Summer60°65°3.3"Fall31°56°2.2"Winter18°25°1.1"20°40°60°80°100°

National Comparison

Warmer than 6% of US counties
Wetter than 1% of US counties
More seasonal variation than 69% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Alamosa County

Climate Verdict

Alamosa County has a cool, averaging 42.5°F annually, arid conditions receiving just 8.7 inches of precipitation annually, rare extreme heat with only 2.05 days above 90°F annually, moderate snowfall of 34.5 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are very cold — January averages 17.9°F. summers are pleasantly cool with July averaging 64.8°F. The 47°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Alamosa County is 3.4°F cooler than the Colorado statewide average of 45.9°F, it is also noticeably drier, receiving 7.5 inches less precipitation than the state average, the county experiences 24.566034265558066 fewer extreme heat days than the state average.

Climate Profile

About Alamosa County Weather

Alamosa: A high-altitude chill

Alamosa County averages just 42.5°F annually, sitting 3.5 degrees below the U.S. median of 46°F. The county receives only 8.7 inches of precipitation yearly—among the driest in Colorado—creating a cold-desert climate typical of high-elevation valleys.

Among Colorado's coldest counties

Alamosa's 42.5°F average ranks it 3.5 degrees colder than Colorado's state average of 46°F, placing it firmly in the mountain county tier. This reflects its San Luis Valley elevation and distance from lower-elevation plains.

Valley isolation creates unique cold

Alamosa (42.5°F) is noticeably colder than nearby Chaffee County (45.5°F) and significantly cooler than Denver-area counties like Adams (50.7°F). The San Luis Valley's geography traps cold air and limits moderating influences from lower elevations.

Frigid winters, cool summers

January lows average 17.9°F while July peaks reach only 64.8°F, with extremely rare heat days—just 2 days per year hit 90°F. Annual snowfall of 34.5 inches reflects the valley's continental mountain climate and long cold season.

Embrace the cold, plan accordingly

Residents need heavy-duty heating systems for sustained subzero stretches and well-insulated homes—cooling costs are minimal with only occasional 90°F days. Winter recreation and seasonal preparation dominate the calendar; spring outdoor work usually waits until May.

Frequently Asked Questions

What is the average temperature in Alamosa County?
The average annual temperature in Alamosa County, CO is 42.5°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Alamosa County get?
Alamosa County receives an average of 8.7 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 Alamosa County?
Yes, Alamosa County receives an average of 34.5 inches of snowfall per year according to NOAA climate normals.
How hot does Alamosa County get in summer?
The average summer temperature (June-August) in Alamosa County is 62.6°F. The county experiences an average of 2 days per year above 90°F.
How cold are winters in Alamosa County?
The average winter temperature (December-February) in Alamosa County is 20.6°F. January, typically the coldest month, averages 17.9°F.

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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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