Great Falls's Climate Data and Its Top-Rated Window Pros
Local risk and climate data for Great Falls, MT sit below, translated into plain terms for a window buyer rather than left as raw codes. 7 installers follow that data instead of a license roster, their rank built from Google's star rating and how many people left one. Checked October 2026.
Google Maps ratings checked · How we rank
6BIECC climate zone · ENERGY STAR Northern zone
What zone 6B means for a Great Falls window
Great Falls falls in IECC climate zone 6B, and ENERGY STAR separately groups Cascade County into its Northern zone for window certification.
Those two numbers, not the brand on the box, set the U-factor and SHGC worth checking on any quote you get in Great Falls.
A Great Falls, MT contractor who can't name either one on request is worth a second question before you sign.
Data: U.S. EPA / DOE, ENERGY STAR, ENERGY STAR Version 7.0 Climate Zones by County/ZIP (Windows, Doors, and Skylights) (V7.0); Pacific Northwest National Laboratory (DOE Building America), Guide to Determining Climate Zone by County: Building America and IECC 2021 Updates (PNNL-33270) (2021 IECC), from the nearest NOAA station 1.4 mi away.
Storm and weather risk around Great Falls
Neither rating changes a window's energy label, but both are exactly what impact-resistance and design-pressure ratings are built to answer for a Great Falls home.
Ask specifically about design pressure and impact rating for Great Falls, not just energy performance, if either risk rating comes back on the high side.
- Strong wind
- Relatively Moderate
- Winter weather
- Very High
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Great Falls window bids come in
- How to Read an NFRC Window Label Four numbers on one sticker decide most of a window's real-world performance. Here's what each one means.
- ENERGY STAR Window Criteria by Climate Zone ENERGY STAR splits the country into four zones, each with its own numbers. Here they are, and why the Northern zone works backward from the other three.
- Impact Windows vs. Shutters in Florida's Hurricane Zones Florida gives homeowners two paths to a protected opening. Here's how each one is tested, and where the HVHZ raises the bar further.
7 top-rated window installers near Great Falls, MT
The order below weighs a Google rating against its review count, the same way this site weighs a U-factor against a brochure claim: on the number, not the name. Treat it as a rating, never as proof of a license, bond or HVHZ approval.
- Irvin Built ConstructionGoogle reviews
- Speedy GlassGoogle reviews
- Anderson Glass Doors & WindowsGoogle reviews
- Titan GlassGoogle reviews
- T C GlassGoogle reviews
- Chinook WindowsGoogle reviews
- Pella Windows and Doors Showroom of Great Falls, MTGoogle reviews