In New Zealand here, and not in a major city - not sure if they have "smog" alerts, though I suspect somewhere like Christchurch might.

However, in this part of the country (Hawkes Bay) we do get a hayever index over the summer months - I am guessing that will start next month - summer starts here about October/novemeber (though so far October has been quite wet!)

I seem to get this at any time of the year - whether riding in heat or the cold, in rain, on humid days, or on hot dry days...

But I hadn't thought about smog or pollen levels til this discussion and am thinking about writing down how much I am affected and the weather/riding conditions and seeing if there is any correlation.

There is a man who trains locally and he wears a mask over his mouth and nose over summer - I am guessing because of hayfever, but I have never actually talked to him