It was 100% humidity yesterday.
There's also the fact that since weather tends to move west to east, more of the ocean seabreeze likely blows over LA vs NYC where it's harder for the colder ocean air to move west. LA does not have as many temperature extremes and some people say they've gone 365 days of the year without turning on AC or Heating.
Missing the point that in the Eastern United States the humidity coming from the Gulf of Mexico is a big factor.
Where?