Climate ZonesColoradoSan Miguel County

What Climate Zone is San Miguel County, CO?

San Miguel County is in IECC Climate Zone 6B (Cold - Dry). Get accurate Manual J load calculations with official ASHRAE design temperatures for San Miguel County.

IECC Climate Zone
6B
Winter 99% Design
5°F
Summer 1% Design
80°F
ZIP Codes
5
Cities
1

San Miguel County, Colorado is classified under IECC Climate Zone 6B (Cold - Dry), a heating-dominated region with dry moisture conditions. With 5 ZIP codes and 1 communities, every HVAC installation in San Miguel County must use the ASHRAE design temperatures of 5°F (99% winter heating) and 80°F (1% summer cooling) for accurate Manual J load calculations.

As a heating-dominated zone, San Miguel County requires robust insulation — a minimum of R-20 in walls, R-49 in ceilings, and R-30 in floors. Windows must meet a U-factor of 0.3 or lower. These requirements ensure homes maintain comfort during the coldest 5°F design conditions.

San Miguel County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 6B in San Miguel County, CO.

Building ComponentMinimum RequirementUnit
Ceiling / Attic InsulationR-49R-value
Wall InsulationR-20R-value
Floor InsulationR-30R-value
Window U-Factor0.3BTU/hr-ft²-°F
Window SHGC0.4Coefficient
Air Infiltration0.15ACH50

San Miguel County HVAC Contractors: Get Your Free Manual J Report

Climate Zone 6B requires precise load calculations. Upload your San Miguel County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with San Miguel County's exact design temperatures (5°F winter / 80°F summer).

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Verify Your San Miguel County ZIP Code

Enter your ZIP code to confirm it's in San Miguel County and get climate zone details.

San Miguel County covers 5 ZIP codes including: 81325, 81423, 81426, 81430, 81435

San Miguel County Design Temperatures

Official ASHRAE design temperatures for San Miguel County, CO, used for accurate Manual J load calculations.

Winter 99% Design Temp
5°F
Heating load calculation baseline
Summer 1% Design Temp
80°F
Cooling load calculation baseline
Summer Wet Bulb
62°F
Latent load (humidity) calculation

IECC Zone 6B Insulation Requirements

Minimum insulation and window requirements for San Miguel County per IECC 2021 energy code.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-30
Window U-Factor:0.3
Window SHGC:0.4

Climate Zone 6B: Cold - Dry - Cold, dry climate with very cold winters and mild summers. Extreme heating requirements, minimal cooling.

Cities in San Miguel County, CO

1 cities and communities in San Miguel County share Climate Zone 6B requirements.

Recommended HVAC Equipment for San Miguel County

Heating Systems

Gas furnace (96%+ AFUE)
Boiler
Typical AFUE
96-98%

Cooling Systems

AC (13-14 SEER, often optional)
Typical SEER
13-14 SEER

Nearby Counties in Colorado

Compare climate zones with other counties in Colorado. Different zones require different HVAC equipment sizing.

Get Free Manual J Calculations for San Miguel County

Upload your San Miguel County blueprint and get a professional Manual J load calculation using official Zone 6B design temperatures. First report is FREE.

San Miguel County design temps
Zone 6B compliant
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