The most frequent pronunciation of the sequence is ɔː. Here are some examples:
applause August auk author cause daunt exhaust flaunt haul launch maul paunch pause saunter taut taunt
However there are some words where the pronunciation is either ɒ or ɔː
Austin Australia Austria auxiliary
The word auction is more usual with ɔː, but some speakers have ɒ.
In words or phrases borrowed from French the pronunciation is əʊ, as inː
au contraire au fait au pair au revoir café au lait chauvinist
The words mauve and taupe also have əʊ.
Aunt is ɑːnt.
Gauge is ɡeɪdʒ.
The sequence <augh> is ɔː in
aught caught daughter fraught haughty naught naughty slaughter taught
but is ɑːf in draught, laugh and laughter.
How could I have forgotten sausage = ˈsɒsɪdʒ and sauerkraut = ˈsaʊəkraʊt? Thanks to Petr Rösel for reminding me. It has also occurred to me that trauma is sometimes pronounced ˈtraʊmə instead of ˈtrɔːmə.