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Why is the sky so hazy?

Jun 05, 2018 | Read More News
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In Pima County, we are used to fairly good visibility when compared to many other areas around the country. The morning of June 5, the sky is quite hazy and our beautiful mountain views are faded. But our monitoring equipment is indicating that air pollution levels are fairly normal for this time of year – so what is going on?

Hazy skiesThe mystery is solved by looking at dew point levels. This morning they were nearly 50 in some areas and we haven’t seen that amount of moisture in the air for a while.

“When moisture meets the normal amount of dust and particulates we have in our desert air, our visibility is obscured,” said Beth Gorman, Senior Program Manager for Pima County Department of Environmental Quality. “It is partly because the moisture droplets in the air reflect sunlight and partly because some of the particles in the air are hygroscopic and grow in size as they absorb the moisture – sort of like a sponge,” said Gorman.

Afternoon breezes are predicted which may help ventilate the area and clear out some of the haze, but the haze could return if conditions become stagnant again. “A great way to reduce the amount of pollution in the air is to share rides, skip vehicle trips and avoid idling our engines,” said Gorman. 

For more information on ways to reduce air pollution and to see real-time air pollution levels, visit the Pima County Department of Environmental Quality.