June 1 is the celebration of Somoza’s defeat in León [1] and August 14 is La Gritería Chiquita, when devout Catholics celebrate being spared from Cerro Negro [2]’s frequent eruptions. The first week of December is huge, with loud, firework-festooned celebrations of the Immaculate Conception.
León celebrates its fiestas patronales on September 24 and the weeks surrounding it.
León’s Semana Santa celebrations are acclaimed throughout Nicaragua as the nation’s most lively. In addition to tons of food and drink, local artisans craft religious scenes in beds of colored sawdust worked painstakingly by hand.
Links:
[1] http://www.moon.com/destinations/nicaragua/northwest-coast/leon
[2] http://www.moon.com/destinations/nicaragua/northwest-coast/near-leon/south-leon/volcano-boarding-cerro-negro