are pollen,dust,seasonal allergies bad in san antomio texas?

There is an invasive species of cedar that really puts out a lot of pollen, but as with all allergies it depends on the person as to whether it bothers you. There are of course other plants and grasses that release pollen, as with most anywhere.

Dust, yes. San Antonio has been in a drought for several years and there are fairly significant water restrictions that get down to no watering of yards or washing of cars.

Hope that helps, I grew up 35 miles west of San Antonio.