Ruaau-Arerenga's 2026 population is now estimated at 1,199. In 2021, the population of Ruaau-Arerenga was 1,199. These population values and projections come from Cook Islands CISO Census 2021 Table 1.05 resident population by usual residence and World Population Review Internal Projections .
| City | 2026 Pop. ↓ | Growth |
|---|---|---|
| Aitutaki | 1,776 | 0% |
| Kiikii-Tupapa-Maraerenga | 1,749 | 0% |
| Nikao-Panama | 1,487 | 0% |
| Titikaveka | 1,276 | 0% |
| Ruaau-Arerenga | 1,199 | 0% |
| Matavera | 1,018 | 0% |
| Avatiu-Ruatonga-Atupa | 974 | 0% |
| Avarua | 974 | 0% |
| Ngatangiia | 795 | 0% |
| Murienua | 794 | 0% |
| Akaoa-Betela | 668 | 0% |
| Takuvaine | 629 | 0% |
| Mangaia | 471 | 0% |
| Pukapuka | 456 | 0% |
| Atiu | 382 | 0% |
| Tutakimoa-Teotue | 274 | 0% |
| Mauke | 249 | 0% |
| Penrhyn | 230 | 0% |
| Manihiki | 207 | 0% |
| Mitiaro | 155 | 0% |
| Nassau | 92 | 0% |
| Rakahanga | 81 | 0% |
| Palmerston | 25 | 0% |