Climate ZonesAlaskaKodiak Island County

What Climate Zone is Kodiak Island County, AK?

Kodiak Island County is in IECC Climate Zone 6A (Cold - Humid). Get accurate Manual J load calculations with official ASHRAE design temperatures for Kodiak Island County.

IECC Climate Zone
6A
Winter 99% Design
12°F
Summer 1% Design
80°F
ZIP Codes
8
Cities
1

Kodiak Island County, Alaska is classified under IECC Climate Zone 6A (Cold - Humid), a heating-dominated region with humid moisture conditions. With 8 ZIP codes and 1 communities, every HVAC installation in Kodiak Island County must use the ASHRAE design temperatures of 12°F (99% winter heating) and 80°F (1% summer cooling) for accurate Manual J load calculations.

As a heating-dominated zone, Kodiak Island 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 12°F design conditions.

Kodiak Island County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 6A in Kodiak Island County, AK.

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

Kodiak Island County HVAC Contractors: Get Your Free Manual J Report

Climate Zone 6A requires precise load calculations. Upload your Kodiak Island County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Kodiak Island County's exact design temperatures (12°F winter / 80°F summer).

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Verify Your Kodiak Island County ZIP Code

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

Kodiak Island County covers 8 ZIP codes including: 99550, 99608, 99615, 99619, 99624, 99643, 99644, 99697

Kodiak Island County Design Temperatures

Official ASHRAE design temperatures for Kodiak Island County, AK, used for accurate Manual J load calculations.

Winter 99% Design Temp
12°F
Heating load calculation baseline
Summer 1% Design Temp
80°F
Cooling load calculation baseline
Summer Wet Bulb
73°F
Latent load (humidity) calculation

IECC Zone 6A Insulation Requirements

Minimum insulation and window requirements for Kodiak Island 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 6A: Cold - Humid - Cold climate with very cold winters and warm summers. Very high heating loads, moderate cooling needs.

Cities in Kodiak Island County, AK

1 cities and communities in Kodiak Island County share Climate Zone 6A requirements.

Recommended HVAC Equipment for Kodiak Island County

Heating Systems

Gas furnace (96%+ AFUE)
Boiler
Cold climate heat pump
Typical AFUE
96-98%

Cooling Systems

AC (13-15 SEER)
Typical SEER
13-15 SEER

Get Free Manual J Calculations for Kodiak Island County

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Kodiak Island County design temps
Zone 6A compliant
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