How does HHN affect daytime touring?

I am planning a return trip to Universal October 24 through 26. I am not planning on attending HHN, but am wondering how, if at all, it affects daytime (or evening) touring of the parks. The crowd calendar is showing level 3 crowds, but I am somewhat skeptical, assuming more people would be coming during this time. Anyone have any input?

Our daytime crowd predictions are pretty accurate, HHN fills the park at night but because it is a separate ticket it doesn’t have a huge impact on midday crowds.

@skubersky, I was considering upgrading our hotel, and found out that both are RPR and HRH are sold out during our stay. Is this also common due to HHN, or does it indicate higher crowd levels than usual?

That’s interesting, it’s a little early for HRH and RPR to be completely sold out, but that is “hell week” so it isn’t unexpected. The 25th anniversary should bring bigger HHN crowds but the daytimes and non-event days should still be slow-ish.