The Arizona Department of Environmental Quality has issued a health watch for air quality on Thursday. Fine particle matters are moving upward - partly due to increased wood burning - and stagnant air is trapping it above the Valley. Residents with respiratory illness are encouraged to limit prolonged time outdoors.
With the lack of winds and a high pressure system, it is possible those particle matter levels will reach an unhealthy level for people sensitive to respiratory issues on Thursday. Cooling on Friday may keep from an extension of the warning, the ADEQ reports. Levels will be re-evaluated Thursday to make that decision.