Sweltering temperatures to continue in North Bay through midweek

Tired of the hot weather? Relief is coming.

The sweltering temperatures felt in the North Bay recently are expected to continue today and Wednesday, but peter out just in time for the holiday weekend.

Temps will climb to 95 today and 92 Wednesday, followed by a cooling trend starting on Thursday that is expected to bring the mercury back down to the low 80s just in time for the Fourth of July.

The past week has been the hottest of the entire year for Santa Rosa residents. Highs have consistently hovered around the 90-degree mark every day - reaching 96 degrees on Saturday and Sunday, and 95 degrees on Monday.

In all this June, there have been six days with highs in the 90s. Five of those have happened since June 20.

What's to blame? A large high-pressure system circling over the Southwest is bringing broiling temperatures from Mexico and Texas farther north and west than they normally would reach, said Steve Anderson, a forecaster with the National Weather Service.

“Mostly the inland areas have seen the hot weather; along the coast, temperatures have been pretty much near normal or on the cooler side,” he said. “The 53-degree (ocean) water temperature keeps the immediate coast rather cool.”

Last June, Santa Rosa had six days with temperatures at or above 90 degrees. In 2014, there were seven days.

Anderson called the month's temperatures “pretty normal” for Santa Rosa.

In Sonoma County, inland areas rarely get a glimpse of the “June Gloom” - a weather pattern that brings low-lying clouds and cool onshore breezes to coastal zones, caused when land heats up more quickly than the ocean. But inland parts of flatter coastal zones, where the Gloom does typically dominate June and often May, haven't seen much if any of it this year, said Bill Patzert, a climate scientist with NASA's Jet Propulsion Laboratory.

This, too, is thanks to the massive rotating dome of high pressure parked over the Southwest.

“It bullied the June Gloom out of the neighborhood,” he said. “It was fine in May, but then this big high-pressure bully showed up and kicked June Gloom's ass.”

Inland parts of Sonoma County are less privy to the low-lying clouds and cool onshore breezes that typify June Gloom because of the hilly coastal terrain, which blocks those types of weather patterns from heading farther east.

Need another reason to hate the high-pressure ridge? Its effect on air quality.

The Bay Area Air Quality Management District issued its fifth Spare the Air alert of 2016, warning the extreme heat, lack of breeze and traffic exhaust will create a perfect storm for unhealthy smog levels on Tuesday.

People who exercise outdoors should only do so in the early morning, as high levels of smog “can cause throat irritation, congestion, chest pain, trigger asthma, inflame the lining of the lungs and worsen bronchitis and emphysema,” the agency said in a news release. And no one wants to deal with that heading into the long weekend.

“Let's just hope this is not a preview of the entire summer,” Patzert said. “That would be grim.”­

You can reach Staff Writer Christi Warren at 521-5205 or christi.warren@pressdemocrat.com. On Twitter @SeaWarren.