County-level fire alerts

• A wildfire that is not yet fully contained within 25 miles of your county centroid (WFIGS source). Prescribed and pile burns are left out; fires listed as 100% contained are left out. A fire can appear on several days in a row while it is still active.
• At least two PurpleAir sensors, at least 2 km apart, within 25 miles report AQI > 150 (Unhealthy or worse) on EPA-corrected 1-hour averages. The readings come from one daily pull and must be no more than 3 hours old when the digest is built; the email gives the measurement time. These are not NowCast values, so they can differ from fire.airnow.gov.

Not emailed: seasonal and weekly risk rankings are not used in emails while the model is being re-validated (see the Scorecard). East-wind / foehn events (Cascade-gap rule, NWS gridpoint) are not yet emailed on their own; they are mentioned only when a fire or smoke trigger also fires. Watch the site banner and your NWS office (weather.gov/alerts) for Red Flag Warnings.

One digest per day max, sent in the morning Pacific time. No email does not mean you are safe: data can be stale, many rural areas have fewer than two sensors, and some triggers are not emailed. Check fire.airnow.gov, weather.gov/alerts and your county alert system. Emails are in English for now; official Spanish-language information is at /emergency/es.

Underlying air quality data utilized by PCSN is sourced from PurpleAir, a network of consumer sensors. Sensors are owned and managed by consumers, therefore PurpleAir does not guarantee data accuracy. All insights and claims are solely made by PCSN.