Wednesday is National Hamburger Day

(CNN, KYMA/KECY) - Fire up the grill, or head for the drive-thru, as Wednesday is National Hamburger Day.

The day wraps up National Burger Month and also ushers-in the summer grilling season.

It's pretty clear how to mark the day, and you can post your burgers with the #NationalHamburgerDay.

The most popular burger toppings range from ketchup to mustard, cheese and bacon and more.

Check with major fast food chains to see if they're running any promotions for the day.

Some fun facts: Americans eat three hamburgers a week on average, adding-up to more than 150 a year. Together with your fellow Americans, that's a collective tens of billions annually.

White Castle became one of the first major hamburger chains in 1921, and McDonald's opened its first restaurant in 1940.