Voter Turnout (Ballots Returned) for the January 23, 2018 Special Election
Number of registered voters in Multnomah County: 511,822
| Date | Ballots Received | Cumulative | Turnout Percentage |
| 12/12/2017-01/03/2018 | 147 | 147 | 0.03% |
| 01/04/2018 | 531 | 678 | 0.13% |
| 01/05/2018 | 11,686 | 12,364 | 2.42% |
| 01/08/2018 | 19,270 | 31,634 | 6.18% |
| 01/09/2018 | 25,849 | 57,483 | 11.23% |
| 01/10/2018 | 10,565 | 68,048 | 13.30% |
| 01/11/2018 | 7,178 | 75,266 | 14.70% |
| 01/12/2018 | 10,698 | 85,924 | 16.79% |
| 01/16/2018 | 10,986 | 96,910 | 19.83% |
| 01/17/2018 | 23,690 | 120,600 | 23.56% |
| 01/18/2018 | 5,353 | 125,953 | 24.61% |
| 01/19/2018 | 13,930 | 139,883 | 27.33% |
| 01/20/2018 | 8,980 | 148,863 | 29.08% |
| 01/22/2018 | 18,564 | 167,427 | 32.71% |
| (Election Day) 01/23/2018 | 46,772 | 214,199 | 41.85% |