Massive fire in NorCal causing flight delays and bad air Aug 2020->
 

I am sure most people have seen this on the news, but the fires near Chico are creating a plume of smoke that is blanketing Northern California, including the coastal areas. The air quality has been very bad the last few days, resulting in cancellation of outdoor sporting events (e.g. kids soccer). The AQ has also caused flight delays at SFO resulting from reduced visibility. If you are sensitive to smoke and plan to be outside you may wish to defer your trip until this clears. The pollution is literally worse than China right now.
As the fires are still burning, and the winds are still blowing, there is no ETA for resolution though we are told things should improve by Wednesday.

Yeah, it was pretty bad air here today, and probably will be tomorrow. It's not horrible, but it's unpleasant to be outside when it's like this.

https://cimg0.ibsrv.net/gimg/www.fly...cd941e932a.jpg

SFO approach on Saturday afternoon

Taken Wednesday afternoon:

https://cimg5.ibsrv.net/gimg/www.fly...3ddd59326a.jpg

Not the best time to visit our beautiful region. I try to put it a global perspective. Many parts of the world have air this horrible on a regular basis. And what we are enduring here in the SF Bay Area is nothing compared to those directly affected by the fires.

All of that said, I've never experienced anything like this in my 29 years of living in Northern California, and in my 22 years prior to that. I see the smoke as I look out my window, across the street. It's awful.

the AQ index is worse now than it was a week ago. Current weather forecasts project rain later next week and better air quality by Thanksgiving. But if you are planning to come here for outdoor activities before that I would cancel the trip.

Up until the past couple of days, the air was reminiscent of the San Fernando and San Gabriel Valley summers through the 70s, with similar AQI readings, and orange / red glow sun sunsets if you were east of the smog. But the past couple days were exceptional. Yesterday, on a drive to/from Fremont, the average visibility was about a mile. From the I-880 / 80 flyover connector, the Emeryville tall buildings were hazy. Last night, lights shining down on sports fields looked like ground fog (made of smoke) was hovering over the turf.

Huge improvement in the inner Bay Area this morning. The air is still not great, but it's no longer hazardous.

Didn't seem like those southerly winds ever materialized. Air is still unhealthy, but not hazardous in the inner Bay Area. Looks like the forecasters are confident that we will get out of the soup tomorrow (Tuesday) evening.

For anyone considering traveling here in the next week, it's actually storms (two) that will be a concern for you, not smoke.

I’ve just returned to the UK after 5 days in SF. My perception is that it’s very difficult to judge the effects merely from the overall air quality figure produced from a number of different sources.

Taking it purely on a visibility level, on Saturday morning Alcatraz was clearly visible from the Fort Mason area, yet the readings were around 180 at the time. Parkrun, the free weekly 5k run at Crissy Fields, was cancelled as a result. On Sunday the readings at 7am were lower, perhaps around 150, yet Alcatraz wasn’t visible at all. Nonetheless, I was able to run a fairly easy paced 5 miles without difficulty.

I think it’s something that, perhaps, is quite localised and the overall figure isn’t much help. I spent one day mostly around SOMA and felt fine, but within minutes of getting within a few blocks of the Ferry Building I could immediately feel the effect on my chest and particularly throat.

Masks are a sensible precaution, particularly if you have any underlying health issues. I was careful, didn’t expose myself for long periods at a time in areas of the city that seemed subjectively worse, and didn’t feel I needed a mask. That seemed to be the view of most people, and actually the percentage of people wearing them is very small.

My advice, which has no professional basis whatsoever, is to go by what you feel from hour to hour - that served me better than any generic official numbers.

I ran an easy two miles yesterday -- didn't notice any effect. I'm coming back from a stress fracture, and I really wanted to get out there. I don't think I'd want to run more than 30 minutes in this air, even if I don't feel any effect. Seems like an unhealthy thing to do.

I managed between 45 and 50, although I made sure I stopped occasionally after extra exertion on the steeper hills - which is really no different to anyone else that’s walking about and getting exercise that way. In other words, listen to your body and be guided by it. I think you generally know when it’s time to ease back.

What’s a bit unknown is any longer term risks caused by absorption into the bloodstream or lungs - I’m really not qualified to give any sort of opinion on that.