How to determine scroll direction without actually scrolling

The mousewheel event is quickly becoming obsolete. You should use wheel event instead.

This would also easily allow you to the vertical and/or horizontal scroll direction without scroll bars.

This event has support in all current major browsers and should remain the standard far into the future.

Here is a demo:

window.addEventListener('wheel', function(event)
{
 if (event.deltaY < 0)
 {
  console.log('scrolling up');
  document.getElementById('status').textContent= 'scrolling up';
 }
 else if (event.deltaY > 0)
 {
  console.log('scrolling down');
  document.getElementById('status').textContent= 'scrolling down';
 }
});

<div id="status"></div>

I know this post is from 5 years ago but I didn't see any good Jquery answer (the .on('mousewheel') doesn't work for me...)

Simple answer with jquery, and use window instead of body to be sure you are taking scroll event :

$(window).on('wheel', function(e) {
    var scroll = e.originalEvent.deltaY < 0 ? 'up' : 'down';
    console.log(scroll);
});

Try This using addEventListener.

window.addEventListener('mousewheel', function(e){
    wDelta = e.wheelDelta < 0 ? 'down' : 'up';
    console.log(wDelta);
});

Demo

Update:

As mentioned in one of the answers, the mousewheel event is depreciated. You should use the wheel event instead.