Arbor Day in Brazil, celebrated on September 21, is a unique ecological observance as the country hosts two Arbor Days due to its diverse climate. The primary celebration occurs on this date, marking the beginning of spring in the Southern Hemisphere, when the dry season ends and the first rains begin. However, in some northern states where September is the peak of the dry season, Arbor Day is also observed during the last week of March to ensure successful tree planting. Many states extend the celebration into Arbor Week, allowing for various events and activities dedicated to the importance of trees and reforestation. This dual observance highlights the geographical diversity of Brazil and the need for tailored environmental practices.