Arizona Air Quality Information

As morning temperatures go down, air quality concerns go up


Have you been enjoying the cool mornings lately? While the cooler temperatures feel great, they do bring some air quality concerns to the Valley, especially as residential wood burning increases. The good news, you can help make a difference so everyone can enjoy the cooler weather!

At night, the ground cools off faster than the air above it. As a result, colder air near the ground gets trapped by a warmer layer of air above it. This pattern is called an inversion and is typically the strongest just before sunrise. Inversions also trap air pollution near the ground and can be noticed on the horizon as the "brown cloud".

Also, as cool air drains off the higher terrain, just north and east of the Valley, overnight winds are typically from the north and east. These light breezes move any pollution generated in the Valley toward the south and southwest.

[Learn more about air quality patterns in Phoenix]

So what can you do to help? If you live anywhere in the Valley, try to limit any activities that produce dust or smoke. Some examples:

  • Use gas or electric instead of burning wood

  • Limit the lighting of fireworks

  • If burning wood for heat or food preparation, use dry wood (burning wet wood releases more particulate matter)

  • Avoid dirt roads

  • If you have to drive on dirt roads, lower your speed to reduce dust production

  • Avoid the use of leaf blowers

  • Ride transit, carpool or telework

  • Eliminate all unnecessary driving and/or combine trips

  • To view the latest air quality forecast for Phoenix, download the Air Arizona App or view the hourly forecast online HERE.