Which should I choose "may" or "might"

[Christine]

Which should I choose "may" or "might"
"What are you doing this weekend?"
"I don't know for sure but I may/might go to London."
How is different between these two verbs.
Thanks.

Christine

[Mister Micawber]

.
No discernable difference as far as potentiality is concerned; it is more a matter of individual habit as to which is used in such a circumstance.

Some may feel (because of the presumed identity of 'might' as past of 'may') that might is slightly more hesitant than may.
.
_________________
Native English teacher at Mister Micawber's

[Chocolatee]

I would choose "might" in your example. I think "might" is leaning towards a greater possibility to do something while "may" is more of saying that the thought of doing it crossed your mind.