December 2006 Air Quality Summary

Air quality during December was in the "Good" category for 5 days, in the "Moderate" category for 16 days, in the "Unhealthy for Sensitive Groups" category for 7 days, and in the "Unhealthy" category for 3 days. Precipitation was 2.55 inches above normal levels in the Puget Sound region, with SeaTac airport receiving 8.00 inches of rainfall. The airport average monthly temperature of 41.5° F was 0.8 degrees above normal for December with a maximum temperature of 54° F on the 14th. A minimum temperature of 27° F occurred on the 18th.

The highest PM2.5 value of 98 µg/m³ was in the "Unhealthy" category (AQI of 170) and was measured on Sunday the 17th at James St & Central Ave site in Kent.
The highest PM10 value of 75 µg/m³ was in the "Moderate" category (AQI of 61) and was measured on Sunday the 17th at James St & Central Ave site in Kent.
The highest 8-hour average for carbon monoxide was 3.7 ppm, in the "Good" category (AQI of 42), and occurred during the early evening hours of Friday the 8th at 148th Ave NE site Bellevue.