Hello - This is a banded argiope, Argiope trifasciata.  They are common in gardens, meadows, yards and near houses.  They build web in tall grass, shrubs and weeds.  It is not poisonous and will not bite unless you are handling a females with egg sac, even then, its bite is not worse than a sting from a bee.

It is a beautiful spider and a beneficial eating many bad insect pests.

For more information, see weblink:

http://www.spiders.us/species/argiope-trifasciata/#range

http://ento.psu.edu/extension/factsheets/banded-garden-spider