Smoke from several California wildfires trapped in the Central Valley

FRESNO, Calif. (KFSN) -- For nearly a month now the Central Valley has been breathing some of the dirtiest air it has ever seen thanks to a ridge of high pressure trapping in the smoke from several wildfires.

As more wildfires break out and until current ones are extinguished this is going to be a problem.

"We're going to be adding extra particulate matter into the atmosphere being smoke, we have haze, we have high ozone level. All those things combined are creating very poor air quality," said Kevin Durfee, Meteorologist, National Weather Service Hanford.

Durfee says the smoke in the Central Valley is from a combination of the Carr and Mendocino Complex fires in Northern California and the Ferguson Fire in Mariposa County.

Most of the smoke comes into the Valley early in the morning and late at night.

"At night we can get a very right down valley wind and that can also bring that smoke down below the inversion and into the San Joaquin Valley," said Durfee. "So we're getting it basically from many different sources."

The Central Valley will have to deal with these conditions for at least another week.

Durfee says a minor cooldown could help a little this weekend but what we really need is a good soaking of rain because any type of wind might do more harm than good.

"The wind is a really critical element for fire behavior and any kind of wind even if it is a cooling wind it could cause a fire to rage out of control," said Durfee.

A minor cool down last weekend that broke the 30-day streak of triple-digit temperatures created some wind at several wildfires. That sparked new hot spots and created more smoke that settled into the Valley.