What Climate Zone is Midland, Texas?

Midland is in IECC Climate Zone 3B (Warm - Dry). Get accurate Manual J load calculations with official design temperatures for Midland.

Climate Zone
3B
Winter Design
35°F
Summer Design
99°F
ZIP Codes
11

Midland, Texas falls within IECC Climate Zone 3B (Warm - Dry), a mixed-climate region with dry moisture conditions. HVAC contractors working in Midland must use the official ASHRAE design temperatures of 35°F (99% winter) and 99°F (1% summer) when performing Manual J load calculations. These values represent the outdoor conditions your heating and cooling system must handle 99% and 1% of the year, respectively — ensuring proper equipment sizing without costly over- or under-sizing.

Zone 3B experiences both significant heating and cooling loads. Midland homes need balanced insulation — R-20 walls, R-30 ceilings — plus windows with U-factor 0.32 and SHGC 0.25 per the IECC 2021 energy code.

Midland Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance requirements for Climate Zone 3B in Midland, Texas.

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

Midland HVAC Contractors: Get Your Free Manual J Report

Climate Zone 3B requires precise load calculations. Upload your Midland blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Midland's exact design temperatures (35°F winter / 99°F summer).

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Verify Your Midland ZIP Code

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

Midland covers 11 ZIP codes: 79701, 79703, 79705, 79706, 79707, 79702, 79704, 79708, 79710, 79711 and 1 more

Midland Design Temperatures

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

Winter 99% Design Temp
35°F
Summer 1% Design Temp
99°F
Summer Wet Bulb
68°F

IECC Requirements for Zone 3B

Minimum insulation and window requirements for Midland per IECC 2021.

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

Energy Code: 2021 IECC

Recommended HVAC Equipment for Midland

Heating Systems

Gas furnace
Heat pump
Typical AFUE
90-95%

Cooling Systems

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

Get Free Manual J Calculations for Midland

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

Midland design temps
Zone 3B compliant
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