Concord, CA: Climate Zone, Risk and Window Requirements

Local risk and climate data for Concord, CA are below, translated into plain terms for a window buyer rather than left as raw codes. Use it to check a proposed spec before you sign, not just to browse.

Licenses checked September 30, 2026 · California Contractors State License Board

3BIECC climate zone · ENERGY STAR South-Central zone

Concord's climate zone, in plain terms

San Francisco-Oakland-Fremont, CA runs a January average near 49°F and climbs to about 73°F by July, a swing that adds up to roughly 2,154 heating degree days most winters, with 1,078 on the summer cooling side of the ledger.

That load is the actual argument for paying up for a better U-factor in Concord, separate from anything a brochure claims.

Zone 3B's requirement is the floor; Concord'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 Concord

FEMA scores Contra Costa County's winter-weather risk as Very Low and its flood risk as Very High.

Winter risk in Concord 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 Concord contractor, not one.

Strong wind: Relatively Low
Winter weather: Very Low

Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).

Guides to finish before Concord 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.

Concord's longest-licensed window installers

Oldest license first, newest last, pulled directly from the state's file. This list isn't for sale.

Schicker Luxury Shower Doors INCWindow and glass contractor · licensed 38 years · 94518Verify license
Diablo Glass INCWindow and glass contractor · licensed 35 years · 94520Verify license
Engineered Construction Services CorpWindow and glass contractor · licensed 30 years · 94520Verify license
Diablo Custom ScreenWindow and glass contractor · licensed 29 years · 94518Verify license
Bestoff Windows And ConstructionWindow and glass contractor · licensed 27 years · 94518Verify license
Superior Window WorksWindow and glass contractor · licensed 21 years · 94518Verify license
Aames Home ImprovementWindow and glass contractor · licensed 20 years · 94520Verify license
West Coast Windows & Doors INCWindow and glass contractor · licensed 19 years · 94520Verify license
Cadco Door & WindowWindow and glass contractor · licensed 19 years · 94521Verify license
East Bay Door And Window INCWindow and glass contractor · licensed 19 years · 94518Verify license
Concord Glass INCWindow and glass contractor · licensed 17 years · 94518Verify license
Window Station INCWindow and glass contractor · licensed 14 years · 94520Verify license

More California climate pages

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