From U.S. Census Bureau: 

The U.S. Census Bureau has immediate job openings! Every 10 years the U.S. Census Bureau is responsible for conducting the nationwide census. While the next census will be taken in 2020, the Census Bureau is recruiting NOW to fill important temporary positions.

These are part time evening and weekend jobs, with very flexible hours. In Multnomah County, they pay $18-$20 an hour.  There is one application portal for multiple job positions. Apply online at http://www.2020census.gov/jobs. This site includes How to Apply, Job Details, Eligibility Requirements, Timelines, FAQs, and more.