Window Climate Specs for Yelm, WA
Yelm sits in IECC climate zone 4C, which sets the energy-performance bar for any window installed here. Below that, a short list of Yelm's longest-licensed window contractors can turn a spec into an actual installed window.
Licenses checked · Washington State Department of Labor & Industries
4CIECC climate zone · ENERGY STAR Northern zone
What zone 4C means for a Yelm window
Yelm falls in IECC climate zone 4C, and ENERGY STAR separately groups Thurston 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 Yelm.
A Olympia-Lacey-Tumwater, WA 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 12.4 mi away.
Storm and weather risk around Yelm
Thurston County's hail risk sits at Very Low and its wildfire risk at Very Low, according to FEMA's National Risk Index.
Hail risk matters for glass and screen durability in Yelm; wildfire risk matters more for the frame material and nearby vegetation than for the glass itself.
Either way, it's a reasonable question to bring to a Yelm installer before you settle on a product line.
- Strong wind
- Relatively Low
- Winter weather
- Relatively Low
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Yelm 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.
Window installers with the longest license records in Yelm
Oldest license first, newest last, pulled directly from the state's file. This list isn't for sale.
- Precision Glass & Mirror INCVerify license
- NW Window Installations LLCVerify license
- Anderson Window CLNG/PrswshngVerify license