What is it with the Central Valley?. Air Quality Index is nasty.

[usonian]

Dense fog past noon in Fresno and Merced.

[The Unmitigated Gall]

1. Probably there's an "inversion layer" like the one that sits over LA most of the year. nt

[Basso8vb]

2. That's my guess, too.

Inversion layer with the mountains on either side trapping all that dirty air.

[Nigrum Cattus]

3. Also Oil & Gas Production

https://www.energyindependenceca.com/californias-economy-is-powered-by-oil-and-gas/
Most of Californians oil & gas production occurs around & between Bakersfield & Fresno.
Link to how much is above - the site is very pro oil & gas - just for statistics

[usonian]

4. Red, Red, pee the bed.

That's a very red area, BUT Congressional District 13, flipped blue! Merced, Stanislaus and San Joaquin counties came through.






Reference: https://www.nbcnews.com/politics/2024-elections/california-us-house-district-13-results

[Clouds Passing]

5. Not normal!

[Old Crank]

6. When I lived there

The air quality was always worse down in the lower valley. The prevailing winds blow from the bay area down the central valley. There is a ring of mountains there that traps pollution and agriculture dust in that bowl. Combined with a normal winter inversion layer up goes the pollution count.

[usonian]

7. I live in those mountains, at least the foothills, and the difference is startling.

Then again, what was a little rainstorm in the valley the other year was 2 feet of snow and howling winds a half-mile in elevation. It's usually 7 to 10 degrees cooler at altitude, summer and winter. It rarely freezes in the valley, maybe a few cold spots, but I have heat tapes on my pipes for good reason.