Washington Air Quality Advisory

We created the Washington Air Quality Advisory (WAQA) information tool to advise you about air quality levels. When there is too much fine particle pollution in the air, your health could be at risk. WAQA bases its advice on lower levels of fine particles than EPA's national information tool, the Air Quality Index (AQI). This allows us to alert you earlier about air pollution levels.

What WAQA is used for

WAQA advises you according to measurements of:

To see the current air quality conditions, look at the map below or go to Washington Air Quality Monitoring Network map for a more interactive version.  Colors on the map refer to the levels of air pollution and related health warnings.

WAQA vs. AQI

The Washington Air Quality Advisory (WAQA) is similar to EPA's national information tool, the Air Quality Index (AQI). Both use color-coded categories to show when air quality ranges from good to hazardous. The difference is that WAQA is based on lower levels of fine particle pollution than the federal AQI. This allows us to alert you earlier to protect your health.

Smoke and dust are some examples of fine particles. Studies show that levels of particles in the air that we previously thought were safe can cause illness and death.

Comparison of the WAQA and AQI health-risk levels

Color – Category Index Value WAQA AQI
  Concentration of fine particles (PM2.5) (µg/m3)

Green dot Green – Good

0–50 0–12.0

0–12.0

Yellow dot Yellow – Moderate

51–100 12.1–20.4

12.1–35.4

Orange dot Orange – Unhealthy for Sensitive Groups

101–150 20.5–35.4

35.5–55.4

Red dot Red – Unhealthy

151–200 35.5–80.4

55.5–150.4

Purple dot Purple – Very Unhealthy

201–300 80.5–150.4

150.5–250.4

Dark Red dot Dark red – Hazardous

301–500

more than 150.4

250.5–500

Go to the Washington Air Quality Monitoring Network map for the full interactive version. Colors on the map refer to the levels of air pollution and related health warnings.