The sequence <ough> is notorious for having many different pronunciations.
1. When followed by <t> it is pronounced ɔː, as in:
bought brought dreadnought fought nought ought sought thought wrought
Exceptions: doughty = ˈdaʊti, drought = draʊt, and at least one of the many places called Houghton (=ˈhaʊtn) or Loughton (=ˈlaʊtn).
2. It is uː only in the word through and compounds thereof like throughout.
3. It is ə in the words borough and thorough (and its compounds).
4. It is əʊ in
although dough furlough though
5. It is ʌf in
Brough chough Clough enough Hough rough slough (=to shed skin) tough
6. It is ɒf in
Bough cough Gough trough
7. It is aʊ in
bough plough slough (= a ditch, a muddy place) Slough sough
8. It is ʌp in hiccough.
9. It is ɒk in lough.