Air Quality in San Joaquin Valley - Sierra Nevada (Fresno: live, floor)

[Schwartzmann]

I've been researching air quality issues in the Sierra Nevada foothills, but have found conflicting information. On the one hand, I've found AQI measures for lower elevation places like Squaw Valley (Fresno County), Catheys Valley, and Caliente that are high (meaning good). On the other hand, I've been reading how air pollutants rise up from the valley floor into the Sierra Nevada on hot summer days to fall again once the air cools... and that the air gets bad up into the Sierra Nevada as well.

What is the reality? At what point (elevation) in the Sierra Nevada does the air quality remain good throughout the summer, if at all?

Thanks in advance for any experience/insight/knowledge you can share.

[BeauCharles]

I worked in Yosemite Valley for a number of years and its air quality is affected by San Joaquin Valley smog on hot summer days. Its at a little over 4,000 ft. The insidious thing is that is ozone, which is odorless and colorless, so you really don't know its there unless you read about it. From the age of 14 on I lived in Mariposa County at 2,500 ft and I always though our air was clean because it looked clean and smelled like pine trees. Had no idea there was actually a pollutant in it.

[expatCA]

Originally Posted by Schwartzmann

I've been researching air quality issues in the Sierra Nevada foothills, but have found conflicting information. On the one hand, I've found AQI measures for lower elevation places like Squaw Valley (Fresno County), Catheys Valley, and Caliente that are high (meaning good). On the other hand, I've been reading how air pollutants rise up from the valley floor into the Sierra Nevada on hot summer days to fall again once the air cools... and that the air gets bad up into the Sierra Nevada as well.

What is the reality? At what point (elevation) in the Sierra Nevada does the air quality remain good throughout the summer, if at all?

Thanks in advance for any experience/insight/knowledge you can share.

One of the problems is not the quality on any given day, rather how many days the air quality at a given time each day is not good. The quality can fluctuate. While the air quality is far better than say the early 70's, it still is not good in most of CA. If day after day you are exposed to air quality that is not good, no matter if not in a real bad zone, it will cause damage.


Try airnow.gov and click on all options for any given day. It is interesting. Remember that even "moderate" is not good day after day after day after ... well you will see.

[Mr5150]

Unless you are very sensitive to air quality one should have no problem with foothill air. Tends to be excellent with the exception of some parts of summer due to regional fires. Given the choice, ill take wood smoke over urban smog any day. Sierra air tends to be pristine. Having a nearby forest fire is different matter. I learned years ago, no bike riding in smokey air.