Climate ZonesWashingtonSkagit

Skagit, Washington HVAC Climate Zone

Skagit is located in IECC Climate Zone 4C (Mixed - Marine). Get accurate Manual J load calculations with official design temperatures for Skagit.

Climate Zone
4C
Winter Design
29°F
Summer Design
85°F
ZIP Codes
12

Skagit HVAC Contractors: Get Your Free Manual J Report

Climate Zone 4C requires precise load calculations. Upload your Skagit blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Skagit's exact design temperatures (29°F winter / 85°F summer).

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Verify Your Skagit ZIP Code

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

Skagit covers 12 ZIP codes: 98221, 98232, 98233, 98235, 98237, 98238, 98257, 98267, 98273, 98274 and 2 more

Skagit Design Temperatures

Official ASHRAE design temperatures for Skagit, used for accurate Manual J load calculations.

Winter 99% Design Temp
29°F
Summer 1% Design Temp
85°F
Summer Wet Bulb
67°F

IECC Requirements for Zone 4C

Minimum insulation and window requirements for Skagit per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-19
Window U-Factor:0.32
Window SHGC:0.4

Energy Code: 2021 IECC

Recommended HVAC Equipment for Skagit

Heating Systems

Gas furnace
Heat pump
Typical AFUE
92-95%

Cooling Systems

AC (optional)
Heat pump
Typical SEER
14 SEER

Related Climate Zone Pages

Learn More About
Climate Zone 4C
View All Zones in
Washington
HVAC Permits for
Skagit, Washington

Get Free Manual J Calculations for Skagit

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Skagit design temps
Zone 4C compliant
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