Metro Phoenix once again under ozone watch - CBS 5 - KPHO

The metropolitan Phoenix area is under an ozone health watch Monday as the area's pollution levels could exceed the federal health standard for air quality.

Ozone is an invisible gas created when other pollutants in the air - such as those created by combustion - are heated by the sun.

Experts said ozone can irritate the lungs and aggravate existing health conditions such as asthma.

Officials say people who are unusually sensitive to air quality should consider limiting their time outdoors.

They also recommended that people avoid waiting in their cars at drive-thru restaurants, unplug electronic devices that aren't being used and fuel their cars after dark or during cooler evening hours.

A strong ridge of high pressure will bring record-breaking or near record-breaking temperatures Monday. Highs in the Valley should be around 114 degrees.

Temperatures will drop slightly by midweek, however humidity levels will be on the increase.  By Wednesday highs will be around 108 degrees and expect slightly below average by Friday.

Only spotty showers/storms are expected mainly over the higher terrain through midweek.  There are signs, however, that some monsoon storms will fire up closer to the Valley by late-week.

Copyright 2012 Associated Press. All rights reserved. CBS 5 (Meredith Corporation) contributed to this report. All rights reserved.