# San Juan · WA — IECC/Building America climate zone by U.S. county, 2021 code cycle

For San Juan · WA, county is San Juan; state is WA; iecc 2021 climate zone is 5; moisture regime is C; building america climate zone is Cold, recorded from its source on 2026-08-19.

- **County:** San Juan _(verified: appears in the quote below)_
- **State:** WA _(our reading, not quoted from the source)_
- **IECC 2021 climate zone:** 5 _(verified: appears in the quote below)_
- **Moisture regime:** C _(verified: appears in the quote below)_
- **Building America climate zone:** Cold _(verified: appears in the quote below)_
- **Changed from pre-2021 IECC:** 4→5 _(verified: appears in the quote below)_

## What the source says

> WA San Juan Cold 4→5 C

## Source

- https://www.osti.gov/servlets/purl/1893981

Last verified: 2026-08-19. Review by: 2028-08-18.
Part of [IECC/Building America climate zone by U.S. county, 2021 code cycle](https://referencesource.org/iecc-climate-zone-by-county/).