What Climate Zone is Adams County, WA?

Adams County is in IECC Climate Zone 5B (Cool - Dry). Get accurate Manual J load calculations with official ASHRAE design temperatures for Adams County.

IECC Climate Zone
5B
Winter 99% Design
7°F
Summer 1% Design
95°F
ZIP Codes
5
Cities
1

Adams County, Washington is classified under IECC Climate Zone 5B (Cool - Dry), a heating-dominated region with dry moisture conditions. With 5 ZIP codes and 1 communities, every HVAC installation in Adams County must use the ASHRAE design temperatures of 7°F (99% winter heating) and 95°F (1% summer cooling) for accurate Manual J load calculations.

As a heating-dominated zone, Adams 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 7°F design conditions.

Adams County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 5B in Adams County, WA.

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

Adams County HVAC Contractors: Get Your Free Manual J Report

Climate Zone 5B requires precise load calculations. Upload your Adams County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Adams County's exact design temperatures (7°F winter / 95°F summer).

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Verify Your Adams County ZIP Code

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

Adams County covers 5 ZIP codes including: 99105, 99169, 99341, 99344, 99371

Adams County Design Temperatures

Official ASHRAE design temperatures for Adams County, WA, used for accurate Manual J load calculations.

Winter 99% Design Temp
7°F
Heating load calculation baseline
Summer 1% Design Temp
95°F
Cooling load calculation baseline
Summer Wet Bulb
63°F
Latent load (humidity) calculation

IECC Zone 5B Insulation Requirements

Minimum insulation and window requirements for Adams 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 5B: Cool - Dry - Heating-dominated with cold, dry winters and warm summers. High heating loads in winter, moderate cooling needs.

Cities in Adams County, WA

1 cities and communities in Adams County share Climate Zone 5B requirements.

Recommended HVAC Equipment for Adams County

Heating Systems

Gas furnace (95%+ AFUE)
Typical AFUE
95-98%

Cooling Systems

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

Nearby Counties in Washington

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

Get Free Manual J Calculations for Adams County

Upload your Adams County blueprint and get a professional Manual J load calculation using official Zone 5B design temperatures. First report is FREE.

Adams County design temps
Zone 5B compliant
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