Fairview Heights, IL Climate Specs + Top-Rated Window Installers
Fairview Heights 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 Fairview Heights on this site, so Google Maps supplies the 5 ranked names you see below. Checked October 2026.
Google Maps ratings checked · How we rank
4AIECC climate zone · ENERGY STAR North-Central zone
What zone 4A means for a Fairview Heights window
St. Louis, MO-IL runs a January average near 32°F and climbs to about 79°F by July, a swing that adds up to roughly 4,547 heating degree days most winters, with 1,476 on the summer cooling side of the ledger.
That load is the actual argument for paying up for a better U-factor in Fairview Heights, separate from anything a brochure claims.
Zone 4A's requirement is the floor; Fairview Heights'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 8.4 mi away.
Storm and weather risk around Fairview Heights
FEMA scores St. Clair County's winter-weather risk as Relatively High and its flood risk as Relatively High.
Winter risk in Fairview Heights 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 Fairview Heights contractor, not one.
- Hurricane
- Very Low
- Strong wind
- Relatively Moderate
- 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 Fairview Heights 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.
5 top-rated window installers near Fairview Heights, IL
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.
- Glass Doctor of Belleville, ILGoogle reviews
- Jacob Sunrooms, Exteriors & BathsGoogle reviews
- Wildwood Roofing & ConstructionGoogle reviews
- 1st Source ContractorsGoogle reviews
- Phoenix Home RemodelingGoogle reviews