Record July heat contributes to rising ozone levels in northern Utah

Posted at 7:10 PM, Aug 02, 2017
and last updated 2017-08-02 21:10:24-04

SALT LAKE CITY – July’s weather was one for the record books, but it spells bad news for ozone levels.

“This has been one of the worst summers for ozone that we've seen here in the valley,” said Jared Mendenhall, public information officer with the Department of Environmental Quality.

In July, air monitors picked up skyrocketing ozone levels in Northern Utah.

"Thirteen or 14 times we exceeded what the EPA has considered a safe level for ozone,” Mendenhall said.

Ozone is created when motor-vehicle exhaust and industrial emissions are mixed with sunlight.

“With that extra heat and that extra UV, you're going to have an ozone problem,” Mendenhall said.

What’s behind the elevated ozone levels? Air quality experts point to unique weather conditions. A high pressure system has stalled over the Wasatch Front.

“This is a lot like the inversions in the winter, so that's trapping a lot of these emissions, so we're starting to see build up day over day where it's not dissipating at night,” Mendenhall said.

High levels of ozone can damage your lungs and trigger asthma attacks or shortness of breath. Sensitive groups should take precautions.

“If you're young or old, or if you have asthma or other respiratory conditions, you're going to want to limit outdoor exposure during the hottest parts of the day," Mendenhall said.

Finding relief from the July heat was difficult.

“It was our warmest month on record and our records began in 1874, so that's a pretty notable record for us to break,” said Christine Kruse, a meteorologist with the National Weather Service.

The National Weather Service says last month’s temperatures averaged 25.3 degrees, a whole degree hotter than the record set four years ago, and 6.6 degrees hotter than normal.

“In July of 2017, our high temperatures were above 90 for all but 2 days, which is a lot of days to be that warm even for July in Salt Lake City," Kruse said.

Cruse says the pattern could last for several months.

“Right now our one month outlook for August is leaning toward above normal temperatures, and so is our three-month so August, September, October, the odds are in favor of us remaining above average.”

Air quality experts recommend reducing ozone pollution, by limiting driving, carpooling, avoiding excessive idling of your automobile, refueling your car in the evening when it’s cooler, and not mowing your lawn until the evening.