HHN. Busy during the day & is it in both parks?

[prince&princess]

Hi all
We are thinking of doing HHN for the first time in september. Will the parks be busier during the days of parties? Also is it in both Universal parks or just one?

Thankyou!

 

[Metro West]

Hi all
We are thinking of doing HHN for the first time in september. Will the parks be busier during the days of parties? Also is it in both Universal parks or just one?

Thankyou!

The parks won't start filling up for HHN until later in the afternoon. September 26 & 27 is opening weekend so the crowds will start wandering in around 3pm or so. HHN is only at the Studios this year.