What Climate Zone is Treasure, Montana?

Treasure is in IECC Climate Zone 6B (Cold - Dry). Get accurate Manual J load calculations with official design temperatures for Treasure.

Climate Zone
6B
Winter Design
-13°F
Summer Design
91°F
ZIP Codes
3

Treasure, Montana falls within IECC Climate Zone 6B (Cold - Dry), a heating-dominated region with dry moisture conditions. HVAC contractors working in Treasure must use the official ASHRAE design temperatures of -13°F (99% winter) and 91°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.

Because Zone 6B is heating-dominated, insulation levels are critical. Treasure homes require a minimum of R-20 wall insulation, R-49 ceiling insulation, and windows with a U-factor of 0.3 or lower per the IECC 2021 energy code.

Treasure Insulation Requirements (IECC 2021)

Minimum insulation R-values and window performance requirements for Climate Zone 6B in Treasure, Montana.

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

Treasure HVAC Contractors: Get Your Free Manual J Report

Climate Zone 6B requires precise load calculations. Upload your Treasure blueprint and get a professional Manual J report in 60 seconds— first report is FREE. Pre-loaded with Treasure's exact design temperatures (-13°F winter / 91°F summer).

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Verify Your Treasure ZIP Code

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

Treasure covers 3 ZIP codes: 59010, 59038, 59076

Treasure Design Temperatures

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

Winter 99% Design Temp
-13°F
Summer 1% Design Temp
91°F
Summer Wet Bulb
62°F

IECC Requirements for Zone 6B

Minimum insulation and window requirements for Treasure per IECC 2021.

Wall Insulation:R-20
Roof/Ceiling:R-49
Floor Insulation:R-30
Window U-Factor:0.3
Window SHGC:0.4

Energy Code: 2021 IECC

Recommended HVAC Equipment for Treasure

Heating Systems

Gas furnace (96%+ AFUE)
Boiler
Typical AFUE
96-98%

Cooling Systems

AC (13-14 SEER, often optional)
Typical SEER
13-14 SEER

Get Free Manual J Calculations for Treasure

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Treasure design temps
Zone 6B compliant
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