sticky-header-autohide.js

var $window = $(window);
var $header = $('.sticky-header');
var scrolling = false;
var previousTop = 0;
var currentTop = 0;
var scrollDelta = 10;
var scrollOffset = 150;

$header.once('init-autohide-header', function() {
  $window.on('scroll', function(){
    if (!scrolling) {
      scrolling = true;

      if (!window.requestAnimationFrame) {
        setTimeout(autoHideHeader, 250);
      } else {
        requestAnimationFrame(autoHideHeader);
      }
    }
  });
});

function autoHideHeader() {
  var currentTop = $window.scrollTop();

  // Scrolling up
  if (previousTop - currentTop > scrollDelta) {
    $header.removeClass('is-hidden');
  } else if (currentTop - previousTop > scrollDelta && currentTop > scrollOffset) {
    // Scrolling down
    $header.addClass('is-hidden');
  }

  previousTop = currentTop;
  scrolling = false;
}

Courtesy of OctoberCMS