About WildfireWindow

WildfireWindow is operated by Oak and Main Developers LLC, 2108 N St., Sacramento, CA 95816. Governed by the laws of State of California, USA. Privacy enquiries: [email protected].

WildfireWindow is an independent tool that makes US wildfire-smoke and air-quality data genuinely usable: the official AirNow number with its provenance, per-city pages, health guides, and free location alerts. Part of the Atmospheric Hazard Network.

Why this exists

Air-quality data is public, free and excellent. The problem is never the data — it is what sits between you and it. Most AQI sites bury one number under advertising, show a raw hourly reading that disagrees with the official figure during fast-moving smoke, or quietly run the pre-2024 EPA breakpoints, which have been wrong since May 2024. On a smoke day you want one number, its source, and how old it is. That is the whole product.

What we will not do

These are commitments, not aspirations, and each is enforced by something in the codebase rather than by intention:

• We will not show a number we cannot source. When the upstream feed fails, the page says "AQI unavailable right now" and names the reason. It never falls back to a cached figure presented as current, and the offline page shows no reading at all.
• We will not make stale data look fresh. Every reading carries the time the monitor observed it — not the time we cached it, which is routinely an hour younger. Past 90 minutes the reading visibly degrades to "last known".
• We will not guess at a standard. Four pollutants (ozone, carbon monoxide, sulphur dioxide, nitrogen dioxide) have no breakpoint table in our engine because we have not verified one against the EPA source document. The engine throws an error for those rather than returning a plausible number. Smoke is PM2.5-dominant, so this does not affect what the site is for.
• We will not manufacture urgency to sell something. Product recommendations appear only when the local AQI is at or above the "Unhealthy for Sensitive Groups" threshold, and the sentence above them names the actual EPA category rather than the scariest adjacent one.

How the accuracy claim is enforced

The AQI engine ships with a test suite of 37 vectors, including the trap case that catches the outdated table: under the 2024 standard a 24-hour PM2.5 of 12.0 µg/m³ is AQI 56, where the pre-2024 table gives 50. npm run validate:aqi runs before every build and the build aborts if any vector fails, so a regression cannot be deployed. The full derivation is on the methodology page, which is the page we point sceptics to.

What we are not

We are not affiliated with, endorsed by, or speaking for the U.S. EPA, NOAA, NASA or the National Weather Service. We display their public data and attribute it on the data sources page. We are not a medical service — see the medical disclaimer. In an emergency, follow your local authorities rather than a website.

Corrections

If a number here disagrees with AirNow for the same monitor, that is a bug by definition and we want to know. Write to [email protected] with the city and the time and we will investigate.

Last reviewed 2026-07-15.