ugh.

What's that mean? I've never seen that before.

Mostly Phen : it means very little wind to blow out any pollutants. Fireplace smoke, car exhaust, etc. will just hang around. The air quality will get progressively worse until the winds kick in again from any direction.

kinda like smog?

We are starting from good air quality, so it should not get too bad.

Last year we had a few days like this with smoke from wild fires and it was the worst.

So that explains the flag on my weather app