I guess it's cultural

Where i live hugging is normal, kissing on the lips is normal. Tongueing, or as US folk say "making out" ,with your daughter would be creepy.

As long as its not more then hugging you should let him do it.  Fathers have a hard time showing they love you - let him hug you.

Although you are 20 years old for your dad you are still the little girl whom he loved so much . No doubt when he does that in public it is very embarrassing . Why not tell him without hurting his feelings not do so in public because people think you are my sugar daddy .Or else your mom can tell him it is not so good to do so in public because you are not his kid daughter but a young lady. 

i dont think so, i would just be thankful you still have your dad around, wish i did

I’m not gonna apologize for saying this: you are truly ungrateful. You know how much this question would hurt you if it was asked by your own kid? How hurtful would it be to heard that your child thinks it’s weird? When all you had wanted is to show them love and affection, when it’s a normal thing ? You are total oblivious on the fact that the majority of the population has depression due to the fact their parents always neglected them, refused to take care of them probably, and also, mainly, strongly refused to be affectionate to their children. Just be grateful. Be grateful he dares to show he loves you , and that a hug, without added morbidity, is just a hug. 

There’s nothing wrong or weird about a father hugging his daughter in public. Nobody will assume he’s your sugar daddy unless you’re kissing him on the lips or something creepy like that. 

It is not weird for a father to be hugging his twenty year old daughter in public. If you feel so weird and awkward with him hugging you in public, sit down with him and let him know how you feel. It should not hurt his feelings to know how his daughter actually feels. Other people will not think he is your sugar daddy.

Just like donny trump

Does he do this for like hour after hour ?  That would be a little constraining.  Otherwise a welcome hug or a goodbye hug should always be welcome.

nope, I hug my two 40 year-old daughters .......................