Westmont's Climate Data and Its Top-Rated Window Pros
Westmont sits in IECC climate zone 5A, which sets the energy-performance bar here no matter who ends up installing your windows. A window license file doesn't cover Westmont on this site, so Google Maps supplies the 10 ranked names you see below. Checked October 2026.
Google Maps ratings checked · How we rank
5AIECC climate zone · ENERGY STAR Northern zone
Westmont's climate zone, in plain terms
DuPage County's normal precipitation runs about 39.7 inches a year, with 42.3 inches of snow, which is a separate question from energy performance but still shapes which window details matter in Westmont.
Moisture and glass performance are handled by different parts of a window's spec sheet, and a Westmont buyer benefits from checking both instead of assuming one implies the other.
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 3.3 mi away.
What FEMA's risk data says about Westmont
FEMA rates DuPage County's hurricane risk as Very Low and its wind risk as Very High.
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 Westmont home.
Ask specifically about design pressure and impact rating for Westmont, not just energy performance, if either risk rating comes back on the high side.
- Hurricane
- Very Low
- Strong wind
- Very High
- Winter weather
- Relatively High
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before Westmont 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.
Westmont'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.
- All Pro ExteriorsGoogle reviews
- 1ST Window Replacement & InstallationGoogle reviews
- DG Windows ReplacementGoogle reviews
- Jay's Window ReplacementGoogle reviews
- JGS Siding ContractorsGoogle reviews
- VOS Doors & Windows - Repair and ReplacementGoogle reviews
- Next Door & WindowGoogle reviews
- Rusco ExteriorsGoogle reviews
- Berg Home ImprovementsGoogle reviews
- Dilworth Windows & Doors Inc.Google reviews