Climate ZonesMississippiWilkinson County

What Climate Zone is Wilkinson County, MS?

Wilkinson County is in IECC Climate Zone 3A (Warm - Humid). Get accurate Manual J load calculations with official ASHRAE design temperatures for Wilkinson County.

IECC Climate Zone
3A
Winter 99% Design
27°F
Summer 1% Design
92°F
ZIP Codes
3
Cities
1

Wilkinson County, Mississippi is classified under IECC Climate Zone 3A (Warm - Humid), a mixed-climate region with humid moisture conditions. With 3 ZIP codes and 1 communities, every HVAC installation in Wilkinson County must use the ASHRAE design temperatures of 27°F (99% winter heating) and 92°F (1% summer cooling) for accurate Manual J load calculations.

With balanced heating and cooling loads, Wilkinson County homes require well-rounded insulation — R-20 walls, R-30 ceilings, R-19 floors — and windows with both U-factor 0.32 and SHGC 0.25 to handle both winter lows and summer highs.

Wilkinson County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 3A in Wilkinson County, MS.

Building ComponentMinimum RequirementUnit
Ceiling / Attic InsulationR-30R-value
Wall InsulationR-20R-value
Floor InsulationR-19R-value
Window U-Factor0.32BTU/hr-ft²-°F
Window SHGC0.25Coefficient
Air Infiltration0.15ACH50

Wilkinson County HVAC Contractors: Get Your Free Manual J Report

Climate Zone 3A requires precise load calculations. Upload your Wilkinson County blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Wilkinson County's exact design temperatures (27°F winter / 92°F summer).

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Verify Your Wilkinson County ZIP Code

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

Wilkinson County covers 3 ZIP codes including: 39631, 39633, 39669

Wilkinson County Design Temperatures

Official ASHRAE design temperatures for Wilkinson County, MS, used for accurate Manual J load calculations.

Winter 99% Design Temp
27°F
Heating load calculation baseline
Summer 1% Design Temp
92°F
Cooling load calculation baseline
Summer Wet Bulb
75°F
Latent load (humidity) calculation

IECC Zone 3A Insulation Requirements

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

Wall Insulation:R-20
Roof/Ceiling:R-30
Floor Insulation:R-19
Window U-Factor:0.32
Window SHGC:0.25

Climate Zone 3A: Warm - Humid - Mixed climate with warm, humid summers and cool winters. Balanced heating and cooling needs.

Cities in Wilkinson County, MS

1 cities and communities in Wilkinson County share Climate Zone 3A requirements.

Recommended HVAC Equipment for Wilkinson County

Heating Systems

Gas furnace
Heat pump
Typical AFUE
90-95%

Cooling Systems

AC (14-16 SEER)
Heat pump
Typical SEER
14-16 SEER

Nearby Counties in Mississippi

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

Get Free Manual J Calculations for Wilkinson County

Upload your Wilkinson County blueprint and get a professional Manual J load calculation using official Zone 3A design temperatures. First report is FREE.

Wilkinson County design temps
Zone 3A compliant
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