Upper Darby's Climate Data and Its Top-Rated Window Pros
Upper Darby sits in IECC climate zone 4A, which sets the energy-performance bar here no matter who ends up installing your windows. A window license file doesn't cover Upper Darby on this site, so Google Maps supplies the 10 ranked names you see below. Checked September 2026.
Google Maps ratings checked · How we rank
4AIECC climate zone · ENERGY STAR North-Central zone
Upper Darby's climate zone, in plain terms
Upper Darby falls in IECC climate zone 4A, and ENERGY STAR separately groups Delaware County into its North-Central 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 Upper Darby.
A Philadelphia-Camden-Wilmington, PA-NJ-DE-MD 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 6.2 mi away.
What FEMA's risk data says about Upper Darby
FEMA scores Delaware County's winter-weather risk as Very High and its flood risk as Relatively High.
Winter risk in Upper Darby 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 Upper Darby contractor, not one.
- Hurricane
- Relatively Moderate
- Strong wind
- Relatively High
- 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 Upper Darby 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.
Upper Darby'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.
- Thermal Quality Window & Door CompanyGoogle reviews
- AMDG ExteriorsGoogle reviews
- Windows PlusGoogle reviews
- Ardmor Windows & DoorsGoogle reviews
- McHUGH ROOFING • SIDINGGoogle reviews
- Window World of PhiladelphiaGoogle reviews
- A to Z Glass and MirrorGoogle reviews
- M & J Roofing SupplyGoogle reviews
- Everman Glass ServiceGoogle reviews
- Southwest Vinyl WindowsGoogle reviews