Well, McDonald's starting serving them in February this year, but any-hoo...Shamrock Shakes used to be available only in March. And because you can only get them for a limited time, I try to buy as many as I can before they're gone again. They are delicious, green, mint milkshakes that I look forward to every year. And now that McDonald's has gotten all fancy, they come with whipped cream and a cherry on top. Although it's still a bit chilly in March, these shakes still make a great treat! Try one!