Missoula's Climate Data and Its Top-Rated Window Pros
ENERGY STAR groups Missoula County into its Northern zone, the U-factor and SHGC target worth checking against any quote you get in Missoula. Below that spec discussion sit 10 installers, their order set by Google rating, since Missoula is outside this site's window license file. A high rating is worth a look, not a finished decision.
Google Maps ratings checked · How we rank
6BIECC climate zone · ENERGY STAR Northern zone
Missoula's climate zone, in plain terms
Missoula, MT runs a January average near 27°F and climbs to about 69°F by July, a swing that adds up to roughly 7,183 heating degree days most winters, with 340 on the summer cooling side of the ledger.
That load is the actual argument for paying up for a better U-factor in Missoula, separate from anything a brochure claims.
Zone 6B's requirement is the floor; Missoula's specific load is what tells you whether beating that floor is worth the extra cost.
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 3.2 mi away.
What FEMA's risk data says about Missoula
FEMA scores Missoula County's winter-weather risk as Relatively Moderate and its flood risk as Relatively Low.
Winter risk in Missoula weighs on U-factor and condensation resistance; flood risk weighs more on sill height and drainage detailing than on the glass package.
Treat these as two separate conversations with a Missoula contractor, not one.
- Strong wind
- Relatively Low
- Winter weather
- Relatively Moderate
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Missoula 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.
Missoula's top-rated window installers, by Google
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.
- Legacy GlassGoogle reviews
- Integrity Window & DoorGoogle reviews
- Tabish Siding and WindowsGoogle reviews
- Grizzly Siding & WindowsGoogle reviews
- Knights Auto Glass And Ceramic Window Tinting Lowest Price GuaranteedGoogle reviews
- NTY WindowsGoogle reviews
- Sierra Pacific WindowsGoogle reviews
- DaBellaGoogle reviews
- Glass Doctor of MissoulaGoogle reviews
- Garden City Paint & GlassGoogle reviews