June 3 Holidays

June 3 is the 154th day of the year. More than 15 holidays and observances fall on the date. Chimborazo Day marks June 3, 1802, when Alexander von Humboldt and Aimé Bonpland attempted to summit Mount Chimborazo in Ecuador — establishing the highest altitude ever reached by humans at that point and providing data that reshaped the scientific understanding of mountain ecosystems. European Bicycle Day was established by the European Parliament in 2022 to complement World Bicycle Day and promote cycling as a key component of sustainable European mobility policy. Insect Repellent Awareness Day was created to promote the use of EPA-registered insect repellents during mosquito and tick season. Martyrs Day Uganda marks June 3, 1886, when the first group of Ugandan martyrs was executed on the orders of Kabaka Mwanga II — 22 Catholic converts killed for refusing to renounce their faith. This page is refreshed each year as new observances are added.