Climate ZonesMontanaStillwater

Stillwater, Montana HVAC Climate Zone

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

Climate Zone
6B
Winter Design
-13°F
Summer Design
91°F
ZIP Codes
7

Stillwater HVAC Contractors: Get Your Free Manual J Report

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

Claim Free Report
No credit card required

Verify Your Stillwater ZIP Code

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

Stillwater covers 7 ZIP codes: 59001, 59019, 59028, 59061, 59063, 59067, 59069

Stillwater Design Temperatures

Official ASHRAE design temperatures for Stillwater, 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 Stillwater 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 Stillwater

Heating Systems

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

Cooling Systems

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

Related Climate Zone Pages

Learn More About
Climate Zone 6B
View All Zones in
Montana
HVAC Permits for
Stillwater, Montana

Get Free Manual J Calculations for Stillwater

Upload your Stillwater blueprint and get a professional Manual J load calculation using official Zone 6B design temperatures. First report is FREE.

Stillwater design temps
Zone 6B compliant
Ready in 60 seconds
Upload Blueprint → Get Free Report

Join 10,000+ Stillwater contractors who trust AutoHVAC