Humboldt County ... Arcata is located in Humboldt County. The county had a population of 134,623 people at the 2010 Census. With it's population of 17,231 people, Arcata represented 12.8% of the county's total.
Here's a chart that shows what day Earth Day is celebrated from 2014 - 2021. Earth Day is celebrated around the world on April 22. Some cities start celebrating a week in advance, ending the recognition of Earth Week on April 22nd. Others host month long events to stress the importance of teaching about our environment. The United Nations celebrates Earth Day each year on the March equinox, which is often March 20, a tradition which was founded by peace activist John McConnell in 1969.
Earth Day 2017, 2018 and further. View below the dates for (among others) Earth Day 2017 and Earth Day 2018. You can also see on which day the holiday falls and how many days it is until this holiday. Significance of Earth Day 2017. Earth Day 2017 is an event observed annually on April 22.