Voter Turnout by day - May 2018 Primary Election
Number of registered voters in Multnomah County: 513,498
| Date | Ballots Received | Cumulative | Turnout Percentage |
| (military/overseas) 04/04/2018-04/25/2018 | 215 | 215 | .0.04% |
| 04/26/2018 | 146 | 361 | 0.07% |
| 04/27/2018 | 2787 | 3148 | 0.61% |
| 04/30/2018 | 7668 | 10816 | 2.11% |
| 05/01/2018 | 11644 | 22460 | 4.37% |
| 05/02/2018 | 4981 | 27441 | 5.34% |
| 05/03/2018 | 6233 | 33674 | 6.56% |
| 05/04/2018 | 3447 | 37121 | 7.23% |
| 05/07/2018 | 5842 | 42963 | 8.37% |
| 05/08/2018 | 10636 | 53599 | 10.44% |
| 05/09/2018 | 8523 | 62122 | 12.10% |
| 05/10/2018 | 5452 | 67574 | 13.16% |
| 05/11/2018 | 11021 | 78595 | 15.31% |
| 05/12/2018 | 5281 | 83876 | 16.33% |
| 05/14/2018 | 15876 | 99752 | 19.43% |
| (Election Day) 05/15/2018 | (updated 5/30/2018) 58180 | 157932 | 30.76% |
Link to statewide voter turnout
Historical Turnout