Traditionally, the beginning of the harvest was celebrated with festivities dedicated to the pre-Christian god Lugh.

It is and was a celebration of the first harvest celebrated on 29th September and also known as the Feast of St. Michael; it would have in the past actually coincided with the first harvest sometime around that date. As with most Celtic Sabbats it actually begins the night before. It usually took place on a hill or eminence, often included a procession around a sacred well, games, markets, races and communal activities of all kinds.

Originally connected with corn, it was extended to the potato harvest as well, when potatoes became the staple diet in Ireland.

Breads and Grain based spirits are the main course of Lughnasa feasts. Some traditions make loafs of bread in the shape of the god. It is also a traditional activity to do wheat weaving as an activity associated with this high day.