The prime season for California avocados are summer and fall. But avocados do not ripen until they are pulled from the tree, so farmers can stagger the harvesting of their crop by allowing avocados to sit on the tree for months before taking them to market.
Fresh avocados can be found on the shelves of grocery stores year-round, even though the summer and fall are the true in-seasons for the fruit. The recent surge in avocado imports has made it easier to stock the shelves with fresh fruit during the winter seasons.
A large percentage of avocados are imported from Mexico, which is the largest avocado producing country in the world. The hot climate in Mexico allows them to harvest avocados later, and bring them to market fresh in the US.
Still, most of the avocados delivered to grocery stores in the United States come from California, and about 90% are of the Hass variety. Hass avocados are the type most people are familiar with, and are cultivated due to their wonderfully nutty and smooth textured flesh.
The key to eating an avocado is knowing when it is ripe. It is ready to be eaten when the skin all the way around its circumference is soft and mushy to the touch, but not too mushy. The skin will have turned a brown or black color, rather than the green color that unripened fruits have.