Halloween Horror Nights - In both parks

[Dream.in.dessert]

I noticed that the regular park hours for Island of Adventure were a later than Universal Studios during the Halloween Horror Nights and I was wondering if Halloween Horror Nights is in both parks.
Thanks

 

[Monykalyn]

HHN is Studios side only.

 

[CAPSLOCK]

They're later in IoA because Studios closes and gets all the guests out, then reopens specifically for HHN.