Climate ZonesTexasFort Bend County

What Climate Zone is Fort Bend County, TX?

Fort Bend County is in IECC Climate Zone 2A (Hot - Humid). Get accurate Manual J load calculations with official ASHRAE design temperatures for Fort Bend County.

IECC Climate Zone
2A
Winter 99% Design
32°F
Summer 1% Design
97°F
ZIP Codes
24
Cities
1

Fort Bend County, Texas is classified under IECC Climate Zone 2A (Hot - Humid), a cooling-dominated region with humid moisture conditions. With 24 ZIP codes and 1 communities, every HVAC installation in Fort Bend County must use the ASHRAE design temperatures of 32°F (99% winter heating) and 97°F (1% summer cooling) for accurate Manual J load calculations.

As a cooling-dominated zone, controlling solar heat gain is essential in Fort Bend County. Windows must have an SHGC of 0.25 or lower, along with R-13 wall and R-30 ceiling insulation. Proper sizing prevents oversized AC systems that short-cycle and waste energy.

Fort Bend County Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance for Climate Zone 2A in Fort Bend County, TX.

Building ComponentMinimum RequirementUnit
Ceiling / Attic InsulationR-30R-value
Wall InsulationR-13R-value
Floor InsulationR-13R-value
Window U-Factor0.4BTU/hr-ft²-°F
Window SHGC0.25Coefficient
Air Infiltration0.25ACH50

Fort Bend County HVAC Contractors: Get Your Free Manual J Report

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Verify Your Fort Bend County ZIP Code

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

Fort Bend County covers 24 ZIP codes including: 77053, 77406, 77407, 77417, 77441, 77444, 77451, 77459 and 16 more

Fort Bend County Design Temperatures

Official ASHRAE design temperatures for Fort Bend County, TX, used for accurate Manual J load calculations.

Winter 99% Design Temp
32°F
Heating load calculation baseline
Summer 1% Design Temp
97°F
Cooling load calculation baseline
Summer Wet Bulb
77°F
Latent load (humidity) calculation

IECC Zone 2A Insulation Requirements

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

Wall Insulation:R-13
Roof/Ceiling:R-30
Floor Insulation:R-13
Window U-Factor:0.4
Window SHGC:0.25

Climate Zone 2A: Hot - Humid - Cooling-dominated with hot, humid summers and mild winters. Significant cooling loads with moderate heating needs.

Cities in Fort Bend County, TX

1 cities and communities in Fort Bend County share Climate Zone 2A requirements.

Recommended HVAC Equipment for Fort Bend County

Heating Systems

Gas furnace
Heat pump
Electric resistance
Typical AFUE
80-92%

Cooling Systems

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

Nearby Counties in Texas

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

Get Free Manual J Calculations for Fort Bend County

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Fort Bend County design temps
Zone 2A compliant
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