South Pasadena, CA Climate Specs + Top-Rated Window Installers
South Pasadena sits in IECC climate zone 3B, which sets the energy-performance bar here no matter who ends up installing your windows. A window license file doesn't cover South Pasadena on this site, so Google Maps supplies the 9 ranked names you see below. Checked October 2026.
Google Maps ratings checked · How we rank
3BIECC climate zone · ENERGY STAR South-Central zone
What zone 3B means for a South Pasadena window
Los Angeles County's normal precipitation runs about 20.1 inches a year, with 0.0 inches of snow, which is a separate question from energy performance but still shapes which window details matter in South Pasadena.
Moisture and glass performance are handled by different parts of a window's spec sheet, and a South Pasadena 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 2.8 mi away.
Storm and weather risk around South Pasadena
FEMA scores Los Angeles County's winter-weather risk as Relatively Moderate and its flood risk as Very High.
Winter risk in South Pasadena 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 South Pasadena contractor, not one.
- Strong wind
- Relatively Moderate
- Winter weather
- Relatively Moderate
Data: FEMA, National Risk Index for Natural Hazards - County-level table, v1.20 (v1.20, December 2025).
Guides to finish before South Pasadena 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.
9 top-rated window installers near South Pasadena, CA
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.
- D&R Auto GlassGoogle reviews
- Budget WindowsGoogle reviews
- MJ'S Windows, Screen & GlassGoogle reviews
- Cliffs Discount GlassGoogle reviews
- Altadena Window Replacement ProsGoogle reviews
- Thurston Screen CoGoogle reviews
- Sunset GlassGoogle reviews
- Pasadena Premier WindowsGoogle reviews
- Pasadena Windows And Doors ExpertsGoogle reviews